Growing With Fishes Podcast Episode 85 Dr. James Rakocy Grandfather of Aquaponics

**The host name and interviewee names get mixed up in this transcript* *

Stephen Raisner: Hey everybody, welcome to the Growing Wishes Podcast. This week, we have a very special guest. Dr. James Rakocy is with us. He is experiencing some internet connection issues, so we’re going to just immediately cut to him rather than doing introductions like we normally do. And thanks, Dr. James Rakocy, for being with us. I do apologize about the loop there; I forgot to mute that screen.

Yeah, I just want to introduce you. So, Dr. Rakocy is one of the original pioneers who helped establish what we all currently understand as commercial aquaponics, as well as home-scale aquaponics. He has contributed significantly to the research that has brought us to where we are today. Thanks a lot for joining us. I’ve been trying to get you on for quite a long time, and I really appreciate you taking the time to be here. Some of our panelists are also having some issues connecting right now, so Marty and Charlie will be joining us shortly. Thanks again, Dr. Rakocy, for joining us.

Dr. James Rakocy: Well, thank you. Thank you for inviting me.
Stephen Raisner: So why don’t you tell everybody a little bit about what you do, and then I have a bunch of questions I’d like to ask you.

Dr. James Rakocy: Okay, well, to give you a little bit of history, I got my Ph.D. in aquaculture in 1980. Then I got a job at the University of the Virgin Islands, and one of my assignments was to develop aquaponics. I was there for 30 years doing that, and then I retired in 2010. For the past 17 years, I’ve been living in Thailand, and I have a consulting firm called Aquaponic Doctors. That’s the quick version.

Stephen Raisner: Awesome. So, why don’t you give us a little bit of background about how you got started, and then at some point, I’d love for you to bring up some of the facts that you were telling me about today. For example, how some people died originally in the beginning when they were cleaning their systems. That was really eye-opening to me when we had a chance to talk earlier.
Dr. James Rakocy: Well, it was not aquaponics that was the issue; it was recirculating systems. I don’t want to give people the idea that aquaponics is dangerous. It was just eye-opening to me about the early days when they didn’t quite understand all that was going on. If you ever have a very deep tank with sludge at the bottom, don’t go in. Don’t get yourself lured into the bottom of that because it could be full of methane or carbon dioxide. Just be careful of that. You could suffocate and die.

Stephen Raisner: So, tell us about the early days and how you got started with aquaponics. You’re one of the founders, so I’m very curious to hear about that.
Dr. James Rakocy: Well, the real early days started off with my childhood interest in fishing in Wisconsin and raising aquarium fish. I had 17 aquariums and sold fish to aquarium stores. I also did gardening in the ground. Fast forward, I got my bachelor’s degree at the University of Wisconsin in 1967. After that, I went to Sierra Leone in the Peace Corps for two years and lived in West Africa. I saw a lot of starvation and hunger there, with babies having distended stomachs from protein deficiencies. That got me interested in food production.

When I got back, I got a master’s degree at the University of North Carolina in environmental biology. At the time, I didn’t even know the word ‘aquaculture’; it was a new term. But I liked the idea of raising fish because I was always interested in them. I subscribed to Aquaculture Magazine, saw a picture at Auburn University of a bunch of foreign students lifting up a net full of clapping fish, and I said, “That’s what I want to do.” So, I applied to Auburn University, graduated in 1980, and while I was there, my research was a sort of precursor to an aquaponic system.

I raised tilapia very intensively in tanks and had different stages for filtration, mainly relying on aquatic plants like water hyacinth and duckweed. I also raised water chestnut and watercress, as well as submerged plants like Elodea and Myriophyllum, which I sold to aquarium stores. I always liked to sell things when I was done raising them.

When I graduated, there was an opening at the University of the Virgin Islands. My predecessor had built a small aquaponic system next to the university. His name was Barnaby Watten, and he had some good results with fish and tomatoes. That interested the director at the Experiment Station, who wanted to pursue aquaponics. Barnaby Watten and his supervisor started ordering tanks, but by the time the tanks arrived, they both left, and I got the job. I stayed there for 30 years and it was a long process of trial and error to finally develop a commercial scale. Probably about 19 years into my tenure there, I’ll just pause here for a second and see if there are any questions.

James Rakocy: Okay, well, let me get into the research part of it. Our first system that we set up, well, we didn’t even have a research facility. We had to build a shed, put in tanks, and install electric lines, water lines, and airlines. The very first system we set up as a demonstration consisted of three and a half metal oil barrels—not the plastic ones. We knew someone who could do welding and was interested in the concept. One oil barrel served as the fish tank, and he made a cone at the bottom of another. Then, we took one oil barrel, cut it in half, and in two-thirds of each half, we filled them with gravel. It was a flood and drain system. The water went from there to a sump and then pumped back up to the fish tank. This first trial lasted four and a half months, and we raised a hundred pounds of food in three and a half oil barrels: about thirty pounds of tilapia, 64 pounds of tomatoes, and eight pounds of lettuce.
We kept that same design, which became the UVI (University of the Virgin Islands) system. We scaled it up to where we had one fish tank that was 3,000 gallons and two hydroponic tanks, each 20 feet long by 4 feet wide. Again, we used gravel and a flood and drain system. We found, through a lot of mistakes—and I don’t want to spend all the time on the podcast talking about all the mistakes—that we didn’t know the right ratios of fish to plants, nor the right pipe sizes. A clarifier doesn’t take out all the solids; it only took out the big, edible solids. About half the solids passed through and clogged the gravel. So, we made a lot of adjustments and got some good results. We learned not to use gravel in commercial systems because it’s just too heavy, takes too much infrastructure, and it’s difficult to plant in gravel. There’s always the danger of clogging.
We overcame the danger of clogging by putting in a false bottom and suspending the gravel about three inches over the bottom of the tank. When we did that, we had accumulation of solids in that false bottom. We solved that problem by putting tilapia in there, letting them swim up and down. They disturbed the solids, which moved down through the system and were taken out by the clarifier. Eventually, we realized that gravel was not good for commercial hydroponics, and we switched over to polystyrene.
We had a system that I’m describing with six replicated systems so we could do controlled experiments with two treatments replicated three times. Based on that, we scaled that up to a hundred-foot-long hydroponics by four feet wide. We had two of those in one system. We also had a smaller fish tank, and we set up those two systems—one we called high-tech and one we called low-tech. The high-tech had the clarifier, a biofilter, and a sump. The low-tech didn’t have any clarification; we just left the solids in there. We quickly learned that you can’t leave the solids in when you have a deep water culture because the solids collect on the bottom of the tank. On a hot day, with all that decomposition, gases from the solids will rise up into the plant roots and suffocate the plants. They won’t be able to get oxygen, and they will die. So, we eliminated the low-tech.

Then we had this biofilter in there. We had rotating biological contactors, and we wanted to see if we really needed these biofilters because we had two tanks that were four feet wide and a hundred feet long—that’s eight hundred square feet of growing area. We took out the rotating biological contactors and just let the water run through those two empty stages. Then we noticed that we had a lot more solids settling out, so we realized at that point that we needed a second stage besides clarification.
That’s where we then came up with using orchard netting, which has a lot of great characteristics. We started feeding more and more food to the fish tank and found out we had tremendous biofiltration capacity in the growing beds. We didn’t need to have a separate biofilter; the growing beds could be the biofilter in deep water culture systems. But the big issue then became that if you have only one fish tank, in the beginning, when you have fingerlings, you don’t have enough nutrients. At the end, they are probably more than enough, and you might have toxicity develop.
Then we decided to build our first commercial system where we had four fish tanks. The fish were staggered over the total growth period of 24 weeks, but we would harvest one tank every six weeks. We upped the number of growing beds to six growing beds that were a hundred feet long by four feet wide. We had three sets of two growing beds. The water would flow out from one growing bed and come back through the other growing bed to a sump and get pumped up to the fish tanks. The design was really good because it eliminated the amount of piping in the water. It was mainly what we call open channel flow: water flowed out through the growing bed and then came back through another growing bed with minimal piping. The sump was right next to the fish tank, so there was very minimal pumping and very little friction loss when you’re pumping. There was only one pump; it pumped up to the fish tanks, and the water flowed by gravity through the whole system back to the sump.
That’s how I learned from my friend who taught me about hydroponic nutrients in South Africa. That was probably 20 years ago. He did all this in South Africa and Kenya because, as you probably know, over there, the government tells you what to grow, and they give you the seed. Then you grow it if you have a farm. He would go around and set up everybody’s farm. They had—I mean, I saw a picture, right? I can’t find it; I’m really bummed out—but I had pictures where you can’t see the end of the farm, and they’re just under posts and shade cloths with four by a hundred-foot beds that drop one inch in eight and then have a sump at the bottom that pumps it right back up. Or, like you said, you can stagger where it pumps up and gravity’s back to the—you know. But they were kind of, you know, playing going down a hill, most of them like that.
I was just in South Africa. I gave a workshop in South Africa, and nobody told me about that. In fact, aquaponics seemed to be very new to the people in South Africa. I thought I made that clear. No, I mean, using the four by a hundred grow bed system, we’re not going to—that’s what sold me on becoming a—if they can do it in South Africa, we should be able to do it in South Carolina. Actually, Merle Jensen from the University of Arizona was the first person I saw doing that. So, I don’t claim that we discovered that either. I think the guy, Merle Jensen, was probably—I don’t know where he—if he developed it or he got it from somebody before him, but he was one of the earliest hydroponics researchers, and he would have been there more than 20 years ago.

We didn’t set up a lot of systems in the Middle East too. Pretty cool because it does—the Middle East goes in. In fact, I can tell you the guy that taught me, his name is David Hill. He now works for Canada International, but he used to be the state representative for South Africa and Kenya. They worked with a company in California, and he hated it and ran. They did have an outdoor hydroponic lettuce farm, which drove all the hydro stores, but he now has gotten out of retail, and he’s—last I heard, he was working for Kin of Nutrients, and that’s—that’s who taught me. And I’m gonna shut up now. I just wanted to bring that up ’cause it sounds the same, except for the aquaponics. But you know, something, when you go from hydroponics to aquaponics, that’s a big—that’s a big change. I mean, they don’t—those systems don’t operate the same at all. For example, in a hydroponic system, the pH is always going up; you have to put acid in there. In an aquaponic system, the pH is always going down; you have to put base in there. So just something like that.
And the other thing about aquaponics is that you’ve got to worry about what you’re going to do with the solids. Solids are a big issue, and you need to remove the solids before you get to the plants; otherwise, they’ll clog the plant roots and cause anaerobic zones. But as I was talking with Stephen this afternoon, the solids are very, very important because most of the phosphorus is in the solids. And another aspect—we didn’t do this. Okay, let me resume the UVI story just briefly. Once we got the four fish tanks and the hydroponic tanks, we could produce about ten to eleven thousand pounds of tilapia a year. These tanks were ten feet in diameter, and I can’t remember how much lettuce we could produce, but we produced a lot of lettuce and many other crops. And then what we did is, well, we had an early commercial scale system, then we upgraded that to the last—to a better commercial scale system, and then even over that, we did a lot of refinement on that. One of our issues was heat, so we did a lot of things to reduce the heat of the water in the water, with shading, for example, and trying to dissipate heat from the airlines and so forth.
And anyway, this happened. We got this final commercial scale system up about 19 years into my being there, and then we started offering training programs. I think in 1999, we started a training program. That was actually before the internet wasn’t really very big at that point, so we didn’t get too many people coming. But I think we had about 17 people the first year we offered it. Later on, and we only had a limited size classroom, later on, they made a conference room, and one year we had 92 people take our short course. Altogether, we had 566 people from 55 countries and 45 states and US territories come down to the Virgin Islands to take a short course. It’s still going on.

Don Bailey is the person who’s still there, and he’s still offering the course. He’s maxing out on the number of enrollees. He can only accept 20 people, but he offers the course multiple times during the year. So, the original system is down there; we call it the UVI system. I think it’s good. I’ve given so many talks, I think I’ve trained over a thousand people. And it’s basically the design, you know, that it’s the basis of the design of aquaponics systems today. But I think there’s a lot more advances. I mean, this was basically telling you the design indicated that we needed to remove the solids, that we needed to aerate a lot. We aerated underneath the plants to keep the oxygen levels up in the roots, and we aerated a lot in the fish tanks. We also did ratio studies so that we knew what the right ratio was. In the beginning, we had way too much fish for the plants, and we got into toxic levels of nutrients, over 2,000 milligrams per liter. Near the end there, we had moderation. We figured out the ratio. It’s not about the fish; it has to do with the amount of fish feed that you put in there. So, the size of the fish and the number of fish that you have is not important from the standpoint of producing nutrients for the plants. You need to have in the range of 60 to 100 grams of fish feed per square meter of plant growing area per day. Now, what’s important for the fish is that when you stock these tanks, within 24 weeks, they can be up to a marketable size. So, the stocking density is important from that aspect. But the main thing is that we had these six things: we staggered the fish production so that the nutrients going into the system were relatively constant, and we staggered the plant production so the nutrient uptake was relatively constant. So, we had a very consistent environment. One thing we did is we had some pretty high densities, but we weren’t actually trying to stress the fish and not to go beyond what’s safe for the fish. So, the key point of these systems is not setting a world record for densities or production levels but to not stress anything so that it comes down with a disease.
James Rakocy: Well, we learned a lot of things. I’m trying to summarize 30 years of work. One thing, let me tell you one thing that Wilson Leonard, my business partner, found out about aquaponics is that it was surprising. Our system was outdoors in the open, and we’re in the tropics where there’s no cold season to kill insects. And, well, Charlie—Charlie, are you out there?
Stephen Raisner: He’s not online. Well, Charlie isn’t joining us yet, unfortunately. Hopefully, he’ll be joining us before the end of the episode here.

James Rakocy: Okay, Charlie was in charge of the biological control of the pests in the plant, so he could speak to this better than me. But we didn’t really have too much pest pressure being out in the open. What Wilson later learned from a project that he did in New Zealand—they hired him to compare hydroponics with aquaponics—so he set up a standard hydroponic system that the industry in New Zealand uses to raise lettuce right next to an aquaponics system. It was a nutrient film technique method, and the trays that raised the plants were right next to each other, one being fed with inorganic chemicals and the other one getting most of its nutrients from the fish, in this case, he was raising grass carp. He put a big yellow strip, about eight inches wide, down the whole length of these end-to-end troughs, one strip for the aquaponics, one strip for the hydroponics. And when he looked at these yellow strips—they’re sticky and they capture insects—when you look at the yellow strip above the aquaponics, very few insects around. When you look at the yellow strip above the hydroponics, it was almost black with insects. And he was using the standard method that they use in England. So that indicates that for some reason, the aquaponic plants can resist pests. And the main reason is that they’re healthier. A plant that’s stressed, like apparently those hydroponic plants were stressed, they, when kind of stressed, create more sugar, and that attracts insects. So, you don’t necessarily have to have an insect problem if you have a really healthy plant. You know, I run across this so many times, even in the tropics, people immediately want to put up a greenhouse. And actually, greenhouses will cause more problems if you have the correct temperature outside. It will cause more problems than they’re worth because once an insect gets in the greenhouse, there’s no natural predators out there to control it, and it’ll run wild in a greenhouse. Then you got to be ordering all these biological control insects like parasitic wasps and so forth. I’ve seen people—I won’t name names—but then you have a perfect climate for raising plants outside, and they go to work and put a greenhouse over it. A greenhouse is only for climates that are not perfect so that you can use the greenhouse in the winter to create an ideal environment or if it’s too hot in the summer to chill it and create an ideal environment. But if you’ve got a good temperature regime outside, you don’t need a greenhouse. So that may be that anybody wanted to discuss that. The greenhouse shuts down in June, and then you start up, and you have production starting in October. Like you said, in the South, they use greenhouses to get through the winter and provide food when the conventional methods won’t be available. By the end of May, beginning of June, shut down for two or three months, clean the whole thing out. You get ready. Okay, that’s hydroponics. But you know, something, that’s when you have a rigid greenhouse. There are a lot of times in the south, if you’re—it depends on your degrees latitude and what the annual temperature regimen is—but you can put a cold frame, you can put a greenhouse frame over there. You’re going there, and when it starts getting cold in the fall, you just simply cover it with a clear plastic membrane, and the greenhouse effect will warm the plants efficiently that you can still keep going with the plants all winter long. Now, this is not good for the northern latitudes because that’s way too cold outside. But in like northern Florida or in Texas, Louisiana, or something like that, you can simply—I saw this in Oklahoma actually—you probably don’t even know, don’t even do a business. It’s called Inslee fun, but he was raising chives, and he had his greenhouse covered in the winter near Oklahoma City, and with just a clear plastic membrane, and then when the spring came, he took the membrane off and just raised all his crops outside. So these membranes are relatively cheap, so you have half your greenhouse and half your no greenhouse. When you start getting into really cold climates, then you need the rigid greenhouses, the diurnal control that goes along with that system. Not without the plastic. When I was in Jamaica, we did just drip screening. We had cold frames the same way that you would for houses, and we just do the thrips screening on it, not to hold any heat or anything like that, but just to keep the bugs off. So I didn’t have to use my IPM, and there’s little IPM as possible. And that’s all we did was his curtains of thrip screening, and that’s all we did because that’s all we had to do. I didn’t have to account for climate control, just like you’re saying. It was that—were you at altitude?

James Rakocy: We were at about 320, a little over 2,000 feet, 2224.

James Rakocy:  You know, that insect screen is secure at sea level. It can get quite hot in there. I always tell people in the tropics that I just had an inquiry last week from Saudi Arabia, where there—I didn’t know this, but there are mountain ranges in Saudi Arabia where you have ideal growing temperatures year-round. The only trouble is, mountains are about 600 kilometers from the populations, and I’m so selling the craft is a little problematic, and they have enough money to move it. It’s okay, hyper train or something. I’m sure these guys—not everybody in Saudi Arabia is rich, I know that the sheiks are now the sheiks got shipped down there, that’s originally more either. But um, so there’s a lot of early research on the exact numbers and ppm levels that you needed to achieve for aquaponics.


Stephen Raisner: So, you want to talk a little bit about why aquaponics can achieve the same levels of tissue mineralization density as hydroponics, but at the same time, why hydroponics requires much higher nutrient levels in the solution compared to aquaponics, which can use, in most cases, a quarter to half the nutrient levels, or even less, to achieve those same nutrient density numbers in the tissue.
James Rakocy: Yes, exactly. For instance, hosted tissue mineralization was like four percent, wasn’t it? Charlie mentioned recently it was a very low percentage, especially for potassium. It was significantly lower for achieving increased growth or even the same growth. It was really interesting. I think he even talked about it last time he was on.
Stephen Raisner: Yep. Well, a hydroponic solution typically starts off at about 2,000 milligrams per liter, and then it’s nothing but uptake, so the levels are always going down. You can start with an ideally balanced solution, but as the nutrients are depleted, the balance will eventually become imbalanced. In an aquaponics system, because the nutrients are being generated every day, you don’t have to start at that 2,000 milligrams per liter level. Actually, we plan our systems sometimes at 200, yes, one-tenth, but I think probably being around 25% of that is okay.
James Rakocy: So, because you have nutrients generated every day, you have a continuous supply. I don’t know if anybody knows all the pathways through which they are generated. I’m sure fish give off some nutrients in dissolved form, and a lot of them probably come from solids that are quickly mineralizing.

Stephen Raisner: And what about Dr. Leonard? He’s not someone I’m familiar with.
James Rakocy: Dr. Leonard came onto the scene after me. He designed a system where he doesn’t discharge any water or solids. What he does is, when he drains to take the solids out, he puts all that water with the solids into another tank where he aerates it continuously. Over about a month, all those solids mineralize and the minerals are left. Then, when he comes into work, he turns off the aeration, and while he’s doing his chores, all the solids settle to the bottom. Let’s say you’re going to add ten gallons of solids to that tank every day. In the morning, he’ll take out ten gallons of clear, mineralized water and pour it back into his aquaponic system. So, he never discharges any solids and only loses water through evaporation. His system is probably the most closed system there is.

He uses lower levels of fish production and does a bit more supplementing. He wrote an article in World Aquaculture Magazine a couple of years back. The gist of it is that if you’re going to do aquaponics, you should be using virtually all the nutrients that come from the fish, which is about 80% of the nutrients for your plants. You have to supplement with potassium, calcium, and a little bit of iron.
James Rakocy: Some people, and I’m not going to name any names, have systems where they’ve undersized their fish so much relative to the plants, or the feeding rate ratio is so low, that they practically have a hydroponic system. Maybe they’re only using 20% of the nutrients coming from the fish, which we would not consider an appropriate aquaponic system.
Stephen Raisner: I’ve come across systems in Germany where they use a decoupled system and a micro screen drum filter to remove their solids, discharging about 7% of the system water every single day. After about 13 days, it’s a complete water exchange. They adjust the nutrient levels in a big tank and then pass it through the hydroponic system once. It’s basically a recirculating fish culture system next to a hydroponic system, but they call it aquaponics, which is a bit deceptive.
James Rakocy: You can tell if people are doing their job by the clarity of the water. If the water is tea-stained, then you know it’s an aquaponics system because it’s tannic acid that’s built up in the water. If it’s crystal clear, it isn’t aquaponics; it’s hydroponics being passed off as aquaponics.
Stephen Raisner: That’s why it’s important to educate people properly about what true aquaponics involves. It’s not just about using the name; it’s about implementing the principles effectively to create a sustainable, integrated system.

Speaker 1: Well, you know, I was talking about the Wilson model. The UVI model is a little different than that. The UVI model has a clarifier which removes some of the solid waste through settling. These are the settleable solids, the heavy solids, and then the suspended solids, the finer solids, are removed in an orchard netting or bird netting tank. Let me just say, the solids, even though we have in our systems clarifiers with 60-degree slopes and conical bottoms, the solids after about two or three days won’t settle out anymore because you get all this biological growth, your biofouling, on the sides of the tanks, and the solids just stick to it. Then they’ll start decomposing into one big mass of cells that will float to the surface. To circumvent that, we put about twenty male tilapia fingerlings in the clarifier, not fed, and they scrape the sides of the tanks. That dislodges the solids which will settle to the bottom of the cone, and you remove solids like three times a day by just opening a valve. In a sewage treatment plant, they have automatic scraper bars to get over this problem, and we use tilapia as our scraper bars. You have to be careful, though, that they don’t get too big because then they become counterproductive. If they get big, they stir up a lot of solids too. So after about 12 weeks, we change them out. We always use male fingerlings, and after 12 weeks, we’ll put in another batch of smaller ones.
On the orchard netting, the bird netting tank, I mean, it probably looks kind of unattractive, but so many interesting things happen in this tank because of the way we’re removing solids. We have this very thin black plastic mesh, like 3/4 inch mesh. For those who don’t know what orchard netting or bird netting is, it’s a netting that they put over fruit trees when the fruit becomes ripe, and that keeps the birds from eating the fruit. So it’s used in the orchard industry. Anyway, we bunch it up in this tank, and the suspended solids will come out not by settling but by the process of interception. The solids hit the plastic and then stick to it, and by adsorption, once it sticks to it, another solid hits it and clumps on. All of a sudden, you see like a crystal growing on these black plastic threads because the threads are so thin. It’s very easy to wash these things off, so we have to clean these things once or twice a week. We don’t throw all the water away when we’re doing it, but our system is such that we need to dump about 5% of the water. Once we decided we weren’t going to dump that 5%, we were just going to put a little pump in there and draw those tanks down and reuse the water. After doing that for about 2 or 3 months, we had the most horrible case of biofouling all over the system. Even four-inch pipes or three-inch pipes were practically clogged up. The growth on the sides of these pipes constricted the pipes, and the water backed up and overflowed the fish tanks. So we needed to really be removing some of the dissolved organic matter from the system.

Speaker 1: Let me tell you the four things that happen in our orchard netting tanks, or you can call them filter tanks. First of all, we’re removing fine suspended solids. That’s one thing. The other thing is that if you allow solids to accumulate and only clean it once a week, some anaerobic zones develop inside the solids, and they will remove excess nitrate, which is important if you’re raising a fruiting crop. So the frequency with which you remove solids can regulate the nitrate levels in the system. Another thing they’re doing is mineralizing the solids. The bacteria in there, you know, we take the solids out, but in the period of a week or half a week, we get partial mineralization. That’s important because it’s providing a lot of trace nutrients for the plants. Andy, can you describe the difference between partial and complete mineralization? Because it’s a term that a lot of our listeners are not familiar with.
Speaker 3 (Andy): Well, at the end of a week, there’s still a lot of solids there, right? So we haven’t broken down all of the solids. We’re discharging some un-decomposed solids. Some of the solids, though, have been decomposed, and the nutrients have been released. When decomposition occurs, the end product is carbon dioxide gas and water vapor. If there was a mineral in this organic compound, that’s now released as an ion that can be absorbed by the plant. We call that partial mineralization. We don’t break down all the solids, but it is important to break down some of the solids.
Speaker 1: And then the final thing that it does, this is something that most people don’t realize, we learned the hard way. One time we decided, why are we worrying about putting in this clarifier and filter tank? It’s a lot of tanks, it’s a lot of expense, and it’s a little bit time-consuming to clean them. It only takes about an hour to clean them in one system. So we put a micro screen drum filter in there. When you look at the effluent from a micro screen drum filter, you don’t see one speck of solids, and it’s perfectly clear water. So we eliminated all the clarifiers and the filter tanks and put the micro screen drum filters there. What happened is that we weren’t removing the dissolved organic matter. You can’t see it, like if you put a teaspoon of sugar in a glass of water and stir it up, you won’t see the sugar, but that glass of water is full of dissolved organic matter. The same thing applies to the aquaponic system. That’s food for bacteria. So what happened is that as the water flowed down the growing beds, bacteria grew on the roots of the plants and formed this gelatinous growth which absorbed this dissolved organic matter. For the first 100 feet, about the first 50 feet, the roots are covered with this gelatinous material which slowed down the uptake of nutrients and oxygen and also affected the plant growth. So with this filter tank, for some reason, we have a filter tank that’s six feet long by two and a half feet wide, and we have water running down one end, and for the sake of space, then it goes to the next thing and comes back again. So that’s 12 feet of length, and by the end of the 12 feet, there’s no solids in it at a flow rate of 10 gallons a minute. During that time, bacteria attached again to this orchard netting are absorbing the dissolved organic matter. So by the time the water goes through these 12 feet, there’s no more dissolved organic matter, and there’s no gelatinous growth on the plant roots. Now, if you don’t use the filter tank, you would then need to install a biofilter after the clarifier. If you’ve ever seen a biofilter where the water is flowing down the length of the biofilter, like a rotating biological contactor, the first part of it will be heterotrophic bacteria that eat the organic matter, and they’re absorbing this dissolved organic matter. Then you get the bacteria that take up the ammonia and the nitrite. But the filter tank does that. So the filter tank is doing four things: taking out fine suspended solids, it could be denitrification to get your high levels of nitrates down, you can mineralize to get trace nutrients produced for your plants, and you can get your dissolved organic matter out of the water.
Speaker 1: Are you still there? You know, everybody’s shocked. Anyway, that’s the crux of the system, and that tank, it looks kind of messy. You see all the solids there, and a lot of people don’t want to clean it. It’s really easy to clean. We just open a drain, and we pick up, we wrap up all the orchard netting, and high-pressure water spraying takes all the solids off easily. You know, they used to have these corrugated plastic media. I forget what they call them, but that’s going to make a wall. No, what’s it called? No, no, no, you’re talking about the new moving bed. Before, they used to have planted corrugated media in a big block of plastic, and then you stack them up to create a trickling filter, usually, or some people then in the summer, but like a wetland, like the bio balls.
Speaker 4: No, this is one solid block of stuff with like a honeycomb in there, little channels that the water flows through. It’s a tangle.
Speaker 1: So instead of having the solids settle to feed, it only has a simple about a half an inch to stick onto the plastic. It’s a plastic sheet. This is cheating, you know, it’s all together. I know I can’t think of the name because they haven’t been around in 25 years. But the trouble with that is that there was one flat sheet of plastic, and you can’t get the solids off. The solids stick so hard it is very hard to clean. Charlie had experience with this at Virginia State University, his first job in aquaculture. I shouldn’t say that. Charlie worked with him for 13 years in the Virgin Islands. He worked a long time down there. He’s a good worker. Really happy to see him doing the work at the Santa Fe College. He said he’ll be joining us here shortly. I just talked to him a couple of minutes ago.
Speaker 5 (Charlie): Oh, gigabytes. Okay, obviously, you know, your plate, that might be him. Someone just joined us here. Richard just joined us. I’m not sure who that is.
Speaker 1: So anybody effectively decoupled? I’m not that familiar with it, and I can see that there’s going to be applications for it, and we’re maybe you have to keep two regimes or two temperatures or something like that. But the key point of it should be that you’re using as much of the nutrients supplied by the fish as possible.
Speaker 5 (Charlie): Yeah, I think I’m online.
Speaker 1: You are. Hi, Charlie.
Speaker 5 (Charlie): Hey, I’ve been listening for a while. You guys are having a great show. I’ve got a little echo on this line. I’m going to drop and try to reconnect.
Speaker 1: That’s it, son, Dr. Rick.
Speaker 6 (Susan): Oh, Susan, I think.
Speaker 1: Okay, yeah. So just don’t talk quite as loud as you were.
Speaker 6 (Susan): Oh, no, not you. Just your microphone’s close to your speaker, so he doesn’t need to be quite so loud when he talks.
Speaker 1: Yeah, I was catching that last part about these settlers, Jim. If I remember, it’s like a vertical tube settler.
Speaker 5 (Charlie): Yeah, vertical tube settler.
Speaker 1: And you had the experience with that, right? And you can browse through that very good thing.
Speaker 5 (Charlie): Yeah, it takes a lot of water. Blue Ridge Aquaculture had those, and it took a powerful force to clean those settlers off. Is there anything new out there for getting solids out these days?
Speaker 1: Well, a lot of the systems here, we are using the radial flow settler. I think instead of the settling clarifier, we actually use a combination of radial flow and then microbials. Let me talk a little bit about lactobacilli. I’m actually big thanks to Marty for being one of the first people to figure that out, along with the guys over at Kentucky State. Both of you guys around the same time discovered that. Marty, do you want to talk about how you got started there?
Speaker 7 (Marty): Yeah, so basically, we were using, I was making labs as a part of the natural farming techniques, which is a lactobacillus serum, and I was experimenting with that. I had put some of it in my worm bin, like the leftovers and stuff like that, and I just sort of poured it on top and also on top with some filter papers from my aquaponic system. I came back like two days later, and it had eaten it clean. I was like, well, that’s kind of interesting. So I started adding some pretty regularly to my aquaponic systems and checking the beds and finding that it’s just breaking down a lot more of the solids to the point where, because I run low-density systems, I don’t have to remove solids nearly as often from, or even just loose material, like you’re saying, the organic material that needs to get removed from my media beds. You know, I just have to do it a lot less often. Like, whereas I probably have to do it, you know, like once every few weeks in some of my systems, you know, I’m doing it more like once every six months. So, but I add labs or Bokashi bran. I’m adding lactobacillus probably about once a week, and then obviously, that’s through the red worm bin. I use that in the root zone. Yeah, I would assume it’s pretty well the population is pretty well established throughout that soil layer as well. So just keeping it a healthy population of the system. I haven’t had any anaerobic issues in any of my media beds, any of the bottom of the dual root zone pots. I haven’t had any root rot, like even on like the cover crop and stuff that I use, or like anything, you know, everything just has extremely healthy white roots, and that’s just been a drastic difference from before. Whereas without that, it would develop over time. You would get anaerobic areas in the media beds specifically that would have to get cleaned out, even with a siphon system and different things going. Like, it seemed like eventually, but you would have little spots where it would go anaerobic, and it would smell different and have unhealthy root systems or root rot or different things like that. Ever since then, I haven’t had any issues with it. I’ve also been doing a lot of ferments with it as well. So like supplementing with fermented fruit extracts or plant extracts. So using lactobacillus in the ferment to extract essentially minerals or nutrients to be able to add them into the system in liquid form. Then I’ll feed, like, let’s say I’m like one of the ones I do a lot is the sour plum that grows out here in front. We don’t, you know, nothing really eats it. They just sort of fall on the ground and normally just go to waste. So I gather, I have my kids gather up a bunch of them into a bucket, and we do a big ferment with like some Bokashi bran and let it break down over about a week or so, and then seal it up and be able to use it as a supplement in the aquaponic systems. All the solids go to the worm bin, and they really love to eat that up and really increases the population a lot in the worm bin. I’ve noticed you use a lot. Anytime I put in the solids from one of those probiotic ferments, the population just goes crazy. So I’ve really seen a lot of benefit from incorporating it on multiple levels in the garden.
Speaker 1: I have a question. Is when you have one system, wouldn’t the lactobacillus population…
Speaker 7 (Marty): Yeah, they would. The only thing that I, the reason that I continue to add is that I feel like it, even though it can exist in aerobic zones, it reproduces better in anaerobic zones. So I wanted to sort of be constantly searching out any places that might be anaerobic and dominating them until they’re gone, and then their population would drop back down. But I do think that there is a constant sort of baseline in my system, even at this point. If I stop adding it, it would probably still be there, especially since I added to my red worm bin as well. Like, I definitely think that now that I have a healthy baseline, I could probably drop off and maybe not do it as much as I do. But, you know, I bought a twenty-dollar bag of it like two years ago, so I use it pretty sparingly when I do do it just because it really doesn’t take much. You know, the population explodes pretty quick after you start that rehydration process.
Speaker 1: What’s the name of the product that you’re buying? Is there a special name to it, or is it just lactobacillus?
Speaker 7 (Marty): Um, I use the Bokashi brand. It’s a rice bran, Bokashi bran from EM1. It’s EM1 Bokashi bran, and the company is Teraganix who makes it.
Speaker 1: How do you spell Bokashi?
Speaker 7 (Marty): Bokashi is B-O-K-A-S-H-I. And that’s essentially a rice bran that’s been inoculated with lactobacillus and then some powdered molasses that is just food for it to take off.



Charlie: Do you have any experience with microbial inoculation, separate from mineralized fish waste or shrimp waste? I’ve seen some biofloc systems using inoculum to reduce waste load. We did an experiment once, remember, when Kelly was there?
Speaker: Yes, we received a small business innovation research grant to test a range of bacteria in our system. I think we had three replicates, but I can’t remember exactly which commercial products we used. They were typically used in soil applications. Unfortunately, I can’t recall the results; it might be because we didn’t apply enough of it, considering our systems were quite large.
Charlie: It’s lactobacillus. You can easily ferment your own from raw milk. The commercial brands provide a few other macronutrients compared to homemade labs, but making it is straightforward. You just need to ferment rice wash, let it soak, and then seal it airtight. It takes about two weeks to harvest your own lactobacillus.
Speaker: That sounds promising. I also wanted to mention something I discussed with Dr. Rakosi. In 2016 and 2017, studies showed that lactobacilli can reduce or eliminate E. coli, Salmonella, and other harmful foodborne pathogens. This is not only when it’s watered in by the root system but also when used as a cleaning agent over typical cleaning agents in food processing areas.
Charlie: What’s the current status on organic certification for aquaponic systems?
Speaker: As of January, the rules state that aquaponic systems can still be certified organic if you adhere to the guidelines and set your organic systems plan properly. However, for cannabis, since it’s not federally legal, there’s no organic standard in the U.S., though Canada is working towards one.
Charlie: Can you talk about the differences between the UVI system and Ken’s system, and how the designs have evolved?
Speaker: The UVI system was heavily stocked, handling 30-40 pounds of fish feed daily, which is much more than most systems. Ken’s system, for example, uses a higher protein fish feed, which reduces the feeding rate ratio. He also incorporates media beds, which affects water chemistry and allows for a lower feeding rate. Ken’s approach includes offline mineralization and reintroducing nutrients back into the system, which is a significant evolution from the original UVI design.
Charlie: It’s interesting to consider the potential of integrating aquaponics with the ornamental fish trade or even tropical fish breeding, which could be more profitable and less regulated than traditional food fish aquaculture.
Speaker: Absolutely, the ornamental fish trade might offer lower barriers to entry and less regulatory overhead compared to traditional aquaculture. However, it’s essential to consider the market stability and demand for ornamental fish, which can be influenced by economic conditions and trends.
Charlie: That’s a valid point. While ornamental fish can be lucrative, the demand for basic food fish remains consistent, making it a potentially more stable aquaculture sector during economic downturns.

Speaker 1:
Back then, you’re looking at your fish tanks. If you say, “I think for today,” you know, I walked by just the other day. I don’t know what war was as I was—oh, you know, I flew in a couple of days ago and I saw—I walked by a store and it looked like they had an incredible fish tank. I had to just stop and have a look again, and it actually was a computer that they had facing the storefront window. It really tricked me; I thought it was an aquarium.
Speaker 2:
I did see an interesting way to make money with these ornamental fish one time when I visited Jim in Thailand. I went to a big market, Chatuchak market, and there’s probably an acre of animal trading going on. On the back wall, there was a big rowdy crowd back there for some reason. Of course, I had to go see what was the rowdy crowd, and I looked back and there were dozens of fish tanks with the betta fish, the Siamese fighting fish. Sure enough, they had guys throwing money, betting on which fish was going to fight to the death. I don’t know if that’s legal in the US, but we could push the limits; there’s probably no law against fighting fish on the books.
Speaker 3:
Yeah, right. So, the Aquaponic Association’s gonna start a new different—we can do a championship for each state, and then they go on to Nationals. That’s kind of how I look at it. I’m setting up myself. I found out that with growing food, I grow so much food I got food that gets wasted. Now we’re doing all these, you know, the composting and stuff like that, you know, for different projects.
Speaker 4:
Yeah, I’m more about—I’d love to feed the community, and I see that, but I also see Steve’s point. You can actually have a viable business, you know, there too, if you could set up the infrastructure first, you know, to build your fish to the like the fish trade. But I also, I’m with Charlie where I want to grow food to eat.
Speaker 5:
Yeah, as long as you’re—sometimes it’s more—you’ll provide far more food for people if you just grow the little fish and then buy the meat and then give them that. Sometimes it’s—oh, but yeah, I know, I’m with Charlie though, to grow food fish when we can. But just—it’s something that I feel is a huge untapped market in aquaponics specifically. There’s a lot of potential that no one’s really going after, and I think if you’re in the country, that’s probably not gonna work you well. But you know, if you’re in a city, a big city, yeah, I think then you can target as long as you can get into any kind of pet stores. I mean, that’s the whole thing, getting in, but even just to wholesalers, you can always mail them across the country. They’re gonna deal a wholesaler license for three hundred dollars in the United States.
Speaker 6:
Let me give you an example. This is not without consciousness with a recirculating system. This is when I first got to Virgin Islands in the early nineteen eighties. I went to a conference in Los Angeles, and there’s a fellow who’s my age now, he’s Telus Weber, and he had a PhD in civil engineering. He set up in his garage these could I sand filters, and he raised huge numbers of feeder guppies. He was selling, and he was strategically located in Los Angeles where the feeder guppies had to come in from either Florida or Singapore or Hong Kong. But he was right there, and, you know, a lot of doctors’ offices and stuff have these fancy Oscars and other attractive fish, and there’s a big demand for feeding up these young to feed big fish with guppies. And I think he was making something like close to $50 a pound per his finger companies, and in his garage back then, he said that he was grossing $250,000 a year. But he was unique because he had incredible densities, and he had his credible good ice, and he’ll—there’s new London design all this because it is a civil engineer, but he was strategically located in good—you could get incredible price for pound basis for these dragons. The other thing too, I used to raise live betas and discus actually, and get pretty ludicrous profit margins on both of those. I was getting two hundred and fifty dollars apiece for fry that were a little over an inch long for betas. Well, at one point, some of the exotic varieties. So, you know, you can get really ludicrous margins depending on how you set up your aquaponics system. And again, fish producing nitrogen as long as they can tolerate the nitrate levels that you’re at, and they’re happy and are going to be healthy, doesn’t matter what species you can have thousands of guppies or you can have tilapia or trout, you know, they produce the same. Now, some of the research that we did a bunch of is herbivorous fish versus carnivorous fish and how that translates into nutrient output. And we found that the carnivorous fish of the higher protein input, like Charlie was mentioning earlier, have much more nitrogen output, whereas the herbivorous fish have much more phosphorous output and tend to be better for flowering crop systems. I had a couple of more comments on the aquarium fish is, you know, often in aquaculture, if there’s a fish that’s a high-value fish, it’s a reason why they’re hard to culture, whether it’s a breeding lifecycle that we haven’t broken or very hard to do in captivity, or you have to culture live feeds because they’re not going to take onto a pelleted diet. So now you’re culturing other animals to culture this animal. And then obviously, you guys, if anybody’s looking to do this, you want a hardy fish that can take the high stocking rates that Jim was talking about.

Speaker 1:
I had a friend recently looking to do a very high-value cichlid, and we brought eight of them in and kept them for half a year. So, as I started looking into it to get a breeding pair, we needed an animal that was about three to five years old, and the breeding pair needed about 500 gallons for two fish. Comes a lot of considerations getting into aquarium fish.
Speaker 2:
Yeah, yeah, yep. They can definitely be far trickier than the normal fish to breed, but again, that’s where the profit margins come in.
Speaker 1:
That’s right. Are there any new species of fish that are going commercial, besides our standard trout and tilapia?
Speaker 3:
I keep my eye on that saugeye, that walleye cross from Wisconsin, and it’s probably the most popular fish up there. A lot of people talk about yellow perch, but I think we’re gonna have to do more work with the hybrids to get better disease resistance and faster growth rates. So, uh, I would be interested in looking at the saugeye, and then now we’re seeing barramundi is kind of spreading across the U.S., sent into Canada too. Personally, I’ve had a lot of great luck with pacu. I think pacu is a really big untapped fish as far as ludicrous growth rate and really good meat. And there’s local farms here raising catfish as their aquaponics fish.
Speaker 1:
Catfish never did well in the circular systems because they’re very prone to disease. If you’re using a channel catfish, you do something like a blue catfish or a flathead catfish; they’re much hardier.
Speaker 3:
I’m pretty sure they’re channel catfish or bullhead catfish, I don’t remember one of the two. Quick note on that, we’ve noticed as well, the lactobacilli made a night-and-day difference with the catfish, even when we netted them and transferred them between tanks, which often, you guys know, will kill a couple of your catfish every time. We didn’t have the deaths.
Speaker 2:
Yeah, I don’t know. I just know that there are three of them here locally in the valley that I’ve been to, and two of them run some kind of catfish, but I didn’t ask them to specify. But I would say, you know, it’s either blue or channel catfish.
Speaker 1:
Yeah, it’s probably channel catfish. And I do see people occasionally will have success; they’ll have these fish in there that they don’t touch for years. You got a big catfish in your tank, but I’m with Jim. I usually recommend not to do catfish because they’re not adaptable to tank culture. And sure enough, I would say three-quarters at least of the people that I tell don’t do catfish, they do it, and then they come down with disease issues.
Speaker 4:
If you’re starting off, you’re new to aquaponics, your best bet is to go with tilapia. That’s the most hardy fish, the most tolerant fish. And if you want to later on go to barramundi or some other species, then learn it with tilapia first. Not outrageous breeding tank needs or anything like that, relatively easy to breed.
Speaker 3:
Well, you know, tilapia is easy to breed, but if you’re… it doesn’t… you can buy… there are hatcheries in the United States where you can buy sex-reversed male fingerlings. And there’s kind of a rule of thumb in the commercial industry that if you’re producing like one to two hundred tons of tilapia a year, you’re better off buying the fingerlings. If you’re producing like 400 tons, then you can look into a breeding program. But it takes too much time, too. If you’re doing a grow-out operation, it takes too much time to do all the procedures for breeding. So, I would not even consider breeding; just buy them. There are a couple of very reputable hatcheries. Ask Charlie online which ones those are, and I would go that way.
Speaker 4:
I was speaking more to the Charlie [expletive] hit the fan scenario. It’s another one of those that you can breed a lot of, and you know, it’s a good protein fish.
Speaker 3:
Yeah, I also think a lot of people online listening to this program, they again probably are starting small, running small systems. And I see a lot of people with a couple of aquariums over on the side with a male and maybe two or three females, and that’s a fine way to get yourself a free number of fry. But as the gentleman I usually teach commercial systems, as he’s talking a hundred tons of fish, these are big facilities. So once you go up into commercial, I would agree to take yourself out of the breeding program unless you’re getting some income on selling fingerlings and fry, which is another good market. There’s a lot of people who want to get into aquaponics, so why not be that small tilapia supplier? Most of my commercial suppliers, they only want to sell me three thousand fish at a time minimum. But all those things to consider, and you also have to remember tilapia is not legal in some states.
Speaker 4:
So, here in Oregon, for instance, you have to go through a pretty rigorous permitting process just to be able to have them. When I asked about it at the county, you know, it was… I didn’t have a lot. They didn’t have a lot of information on that other than they knew that I had to get some kind of permit, and it was… I don’t know, it just seemed like it was kind of a runaround as opposed to some of the other ones. And ultimately, for me, since my primary interest was growing medicine, I just ended up going to the pet store, getting some koi and some goldfish, and you know, that’s just pretty much what I’ve done. I did use some… what was it… a couple of rainbow trout that we had for a little while outdoors, and we raised them for about ten months or so before it got really hot, and then harvested those, and it went relatively well. But again, that’s all small home systems. That feels like… like each other’s like, “Oh, it’s not that’s a nine-day difference.” But I do think that a lot of people listening, like you’re saying, are the small home grow, you’re wanting to start a system. And if you’re just starting out, we talked about this a lot. If you’re just starting out, I highly recommend just going to the pet store, buying some goldfish, and getting your system established and learning some stuff. And if you, you know, just like anything else, if you’re thinking about scaling up to commercial, then you know, just take those steps that make sense and learn as you go.
Speaker 3:
I definitely would shy away from, you know, swinging for the fences in a situation like trying to farm fish like Steve was talking about. Like, he has extensive experience in the trade, so it’s a little different for him to talk about.
Speaker 4:
Oh, I love it when I worked like a porn actress. I had multiple people come to say, “Hey, I built a 12,000 square foot aquaponic system, and what’s iron, and how do I fix it?” But they have, you know, 60,000-70,000 gallons of system, no idea what either one of those things are, and I’ve had that call happen to me three separate times.
Speaker 3:
Yeah, you see, you know, you order 500 tilapia, and now 400 of them are dead because, you know, it’s… I’ve never raised anything similar. Not cool.

“Let me ask this, Charlie, and Dr. Rakosi, what are the craziest, maybe top three or top five, things going on in my system? I think the other one that I can add is I’ve had three calls from Australia asking me what the level of uranium or radon is acceptable in their water, which is also a hysterical question, huh?”
Dr. Rakosi:
“Um, I can throw out a couple. I’ll let Jim have a couple of minutes to think about it. I had a client one year having problems with their ammonia, and this may have been a time Jim and I were in communication helping somebody. But the system seemed to work fine for a long time, everything was running well. And when there’s a water quality problem, I tell my students you have to put on your detective cap. It’s something that you’re overlooking or you did wrong, you’re feeding out of ratio. But again, the system had been running well, but this group was, I think we determined once that they were, when they were cleaning their rafts, they were bleaching their rafts and cleaning both sides of the rafts, including the underside where all your biofilm was. So a simple suggestion, where you know, don’t do that, just scrub off the top of your raft lightly, get your raft right back on the water surface to preserve your bacteria, that saved that facility a lot of time and a lot of money.”
“And then the other one I want to mention is a lot of people have the opportunity in urban settings to get into a building, maybe a cheap lease. Maybe somebody’s got something that they’re giving for $1 on a short-term lease. And so you can get in these facilities and build up, but if that lease isn’t a long-term lease, that landlord has the right to pull that lease any time they want. And I’ve seen a facility get up and established, start their marketing, teaching some courses, and then they got a two-week notice to vacate their facility. So I always caution people about that and to take care of that lease.”
“And I don’t have a third one on top of my head, but I always caution everyone to make sure they understand what their source of water is before they jump into this. If you’re going big-scale, you want quality and you want quantity. So, I’ve seen people buy property and then have their water analyzed and realize they can’t use it for aquaculture.”
“Those are a few things. The other good one that I remember is I had someone ask me when I was working in the pet trade if they could legit pleasure themselves into a fish tank to feed newborn fry. Like a hundred percent serious with a straight face, was not joking at all.”
“Oh, okay, I got a couple. One was actually not aquaponics, it was about a biofloc system. This was a woman on another island in the Caribbean, and we spent… we had a biofloc system, there was a two hundred thousand gallon tank. And so anyway, she spent the money to build this tank, yes, she ordered the, like, for being vertical lift aerators. And I went, I took several trips to visit the facility, and when it was done, she harvested fish after about eight months, and they were really small. I said, ‘Why are they so small?’ And I said, ‘Are you feeding them, you know, this amount of feed every day?’ And she said, ‘No, she said feed is expensive, you don’t know anything about business. I’m not feeding, I’m hardly feeding them anything.’ I can’t always get a PhD in academic accounting, don’t put anything in there, it was too much.”
“Another one was a sad story, and this is a really true story. This was in, there was a social program in Philadelphia, and they had a million dollars worth of funds to build an aquaponic system with basil. And they hired a consultant that was advertising online, and he designed what a big, also designed this system and everything like that. Then there was a, you know, critical proposal, and a lawyer sent it to me, and he said, ‘Can you review this for me?’ And I said, ‘They didn’t say anything about paying me, you know, you know, would have taken maybe half a day to sit down there and then go over the system.’ And they do all right, ‘You gonna pay me?’ He says, ‘No, we only have enough money in the budget for one consultant, and that’s the one we hired.’ You can’t go into the doctor’s office and ask for four hours of time or the lawyer’s office. I said, ‘If you can’t pay me, I’m not gonna review it.’ So I actually didn’t open the envelope, they sent it back when I had to pay $3 for Priority Mail, was sitting after the guy. They built the system, and it turns out that consulting, the whole thing about aquaponics, and Don Bailey and I were working on a system at Rutgers University. And Don was up there by himself once, he went over to view the finished system, and I asked Don, ‘Well, if they would start bulldoze it down, start over again.’ Maybe this guy just had, yeah, what, airlift pumps all over the place, he had a net separating the fish component from the plant components, yep, not a walnuts greens, you know, just admit it was horrible, and they never actually, and then you know what they ended up doing? He blamed it on me because I, they said, ‘Well, review the proposal.’ I remember both of those stories, Jim, I was there during those times.”
“Another one that everybody here is gonna make this mistake one time in their, and their fish career, and I tell my students, and I do see it still, is that if you don’t take both ends of your pump and your water hose out, you’re gonna get a back siphon after you leave your facility, and you’ll empty tanks right onto the ground. We saw that before at UVI, I’ve seen it other times in my career.”
“Yeah, we had employees at Aquaponics Source flood, then flood our lab, and then Leslie, our neighbor’s unit. So that, with a bag of lettuce and basil, and usually staved off their anger.”
“Yeah, and I think most of your listeners, especially if they’ve stuck around this long tonight, have an understanding of aquaculture. But we all know that when we shift the pH up by adding our base additions, we’re also shifting the ammonia into a more toxic phase. So I remember one time at UVI, we had a fingerling system, we probably had 50,000 fry and fingerlings in this system, and one of the technicians came in after a weekend where nobody had checked the pH or the ammonia levels. pH dropped rapidly, um, he added the base, the calcium hydroxide, and as it went into all 12 tanks, it instantly shifted that ammonia to the toxic form, and the fish just died out. And we killed every fish within probably five minutes. Well, before they died, they all jump out of the water, it’s like a right.”
“Yeah, and you know the pH can go from seven down to 4.5 in just a matter of a couple of days, so you really got to be on top of it.”

Dr. Rakosi: That’s right, that’s why I’m a big proponent of maintaining alkalinity and making sure you’re testing alkalinity as well because that helps prevent that sudden crash. But you want your alkalinity to be in a solid form that can buffer the system so that the pH doesn’t crash.
Steve: Why don’t you talk to Dr. Rakosi here?
Jim: So, people kind of take our advice, they’ve run it for years, and now I’m seeing some changes in the way people manage their systems. Steve is kind of adamant that we stop using KOH and instead use more products that are designed to increase the alkalinity, not just a sudden shift in pH. I would love to hear you guys talk about that a little bit.
Dr. Rakosi: Sure. I’ve actually run a bunch of organic studies on organic hydroponics and how, in organic hydroponics, their main goal is 100% stability—maintaining as stable as possible alkalinity and pH and not letting that shift because that’s what those microbes want in order to be maximally efficient for remineralization of whatever it is they’re trying to remineralize. In our case, we’re trying to remineralize fish waste. In some cases, they’re using cow manure or human manure, chicken manure—it varies. Pig manure is very common right now. I’m trying to do a lot of work with it because there’s a lot of pig manure for food production. So, if you take those things, and that’s where this research came from, they discovered that when alkalinity goes below, I believe it was 30 parts per million or 28 parts per million, somewhere in that range, it cuts bacterial replication in half. So, if I’m using something that is like KOH or Ca(OH)2, I’m not getting that extra additional buffer. Yes, I have the hydrogen ions which helps them, and that will give its own buffer capacity to a lesser extent, but it’s not the same as calcium and it’s not, or silica for example.
Steve: I’m a bigger proponent of potassium silicate because again, it provides a more stable pH change. I used both of these when I worked a lot with planted aquariums for the same reasons that we use them in aquaponics. Are you talking about again having it in a solid form that’s going to slowly release?
Dr. Rakosi: Yes, these are all powdered forms. I like to use potassium bicarbonate or calcium carbonate or a really fine powder dolomite. It will also work, or potassium silicate. The two that I like the most are potassium silicate and calcium carbonate.
Charlie: Well, what we had, we had a base addition. We know our system was twenty-nine thousand gallons, 110 cubic meters, and we had a base addition tank that slowly, we would add like a thousand grams per liter of Ca(OH)2 or K2CO3. It was slowly dripped into the system. I mean, there was a real trickle of a flow into the system, which immediately pumped the water to 8,000 gallons of water. So, there’s no fluctuation in pH at all. Our pH was extremely stable. It would, if it would go down like a part per million, then two days later we would add some more. So, we had a base addition. pH was a big issue in the beginning because we didn’t know where to put the base. If you put it in the fish tank, you got a hotspot of really high pH. If a fish swims to that, it’ll damage their scales. And if you put it in the hydroponic, there’ll be a plug flow of high pH; it’ll damage the roots. But because we have this base addition tank just trickling the, you know, the high, like dosing it’s like a dosing thing, but we didn’t have a doser. It slowly added to the system, so there isn’t really much fluctuation of pH.
Charlie: Charlie, don’t you agree that we didn’t really have much fluctuation of pH?
Charlie: You know, because we maintained it, and we were always on top of it.
Steve: I think what Steve’s alluding to is more keeping it very stable over time. As you said, sometimes they could rapidly drop from seven down to five. So without that alkalinity buffer, our systems can have that trend. I’ve found the aquaponic system that we ran to be a little more stable than these nursery systems with drum filters, and that was a sudden change. But I think that the KOH and the Ca(OH)2 and the iron that we put in our water over time, that’s all we added. How was there 13 years, Jim was probably over 30, but we didn’t go out and buy any other supplements. I think I once looked at potassium silicate for a 29 thousand gallon system to bump it up to, I forget what Steve had said, what’s your recommendation, 5 ppm for potassium, for silica?
Steve: For silica, I prefer to keep my silica what we found gives the best results for lettuce is above 60 PPMs. And the reason is that it helps for all of the pathogenic reasons, an increase in heat stress as well, reduces bolting, but it also increases crispness when it goes to shelf.

Speaker 1:
But also, I had one other question on the note that Charlie had. What supplementation, if any, have you guys added?
Speaker 2:
We never supplemented. A lot of times, we never saw it, and when I watered it, sometimes it came up zero because I’ve noticed molybdenum. I’ve actually seen in a commercial system where a little bit of it was omitted, and the plants shipped it out. It was a large vegetable system, and it was a lettuce system. They were running super high nitrogen levels, and the plants basically plowed through it all, and they were showing really strange deficiencies because the lack of molybdenum was affecting their ability to process the nitrogen.
Speaker 3:
That’s why I was curious. At Steve, I was saying, I was telling everybody, I wanted to remind that we only supplemented with calcium, potassium, and iron. So, in the years I was there, and as far as I know, the years everybody was there, we never went out and bought Epsom salts to add magnesium. We didn’t add molybdenum. Again, twenty-nine thousand gallon system, and we were trying to get farmers to adopt these systems in remote locations where a lot of things aren’t available.
Speaker 4:
I would agree. I think there were times when molybdenum was probably nothing, so maybe adding it would have enhanced the nutritional quality of the plant tissue, but we would have had to look at that data too. As Marty was talking about earlier, there’s some research out there showing that on these very low nutrient streams, we can get as good or better yields, and at times better nutrient quality as well. Just because sometimes it came up zero, sometimes zero point zero, doesn’t mean it was zero point zero four. So, there could have been trace amounts that were sufficient, you know? And what that showed was that the systems were so balanced in the input and the uptake of that element that we never registered much more than that, so it was in check.
Speaker 5:
We never did, actually, well, we did one time. I did a side-by-side comparison, and we found hydroponics to be the same as the aquaponics. This was with a deep water culture system. But when you run a system for years, we didn’t change the water for years. Maybe we weren’t getting like a hundred percent growth that somebody else someplace else can get, but we were getting good growth and producing a good marketable crop.
Speaker 6:
When we did one experiment where we ran, we wanted to, in the early days, prove the sustainability of the system. So we produced lettuce for three straight years. We had about a hundred and fifty lettuce harvests, and it was still pumping out lettuce. We would get dips in the summertime when it got really hot, and we had pythium problems, which compounded things a little bit. Different than when the cold temperature, you can look at it. I graphed this. We definitely had a bar graph of this. Over 150 harvests, we only lost seven harvests, I think, due to a hurricane that came through.
Speaker 7:
Rather, three years, aquaponic systems recycling 98% of the water and buying no fertilizer, and getting 27 cases of lettuce a week. That’s amazing. Although we could have gotten more than that, we didn’t have the ideal temperature. That was one thing we suffered with. It was a little warm, definitely in the summertime.
Speaker 8:
And then, as we were all, that’s it, that’s a great question. So a lot of people live in warmer climates. What varieties of lettuce work great in the tropics? If you go to Johnny’s, you can look up, they have a category of heat-tolerant lettuces. And the other thing to consider is shade. But in the middle of the day, we never had shade cloth, but you can get blazingly hot, especially where I live in Thailand. So growing about 10 a.m. in the morning to 2:00 or 3:00 in the afternoon, you should probably shade them.
Speaker 9:
That’s what I think, Charlie. We have shade cloth. Our thinking wouldn’t have the wilting in the middle of the day in those hot summer days. Now, I was in Texas a couple of years ago. I spent a year, a little over a year, running a farm in Texas, and we were using 70 and 80 percent shade cloth on our hoop houses during the summertime.
Speaker 10:
Yep, we switched mostly to basil at that time. Basil was thriving in that heat, but we had to shade it that much. I just put a 50% shade cloth on top of my greenhouse yesterday here in Santa Fe. That slows down your growth. We get too much sun in Santa Fe, so we have to block some of the sun.
Speaker 11:
No, no, um, Ken’s had really good luck with, say, taking something like that and with basil or rosemary, oregano, and you take it, and you seed your aquaponic farm, or you can take it, blend it in with some really high-grade salts, and make an herb salt or an herb butter. I, not Ken, there’s another aquaponic farmer I was working with previously that makes an herbed butter out of their stuff, and they take butter and melt it down with the herbs that grow on their farm and then resell it.
Speaker 12:
So, you know, a little bit of value-added can go a long way as well. Yeah, there’s a lot of value-added stuff that you can do. The big one that I always talk about is the Miles Hairston and what’s that operation called, and planning in Illinois?
Speaker 13:
I don’t even know that was, that was Aqua Ranch.
Speaker 14:
Only Aqua Ranch. Well, he, his wife made a basil vinaigrette when they were selling the big leaves to Whole Foods in Chicago, and then the smaller misshapen leaves, they made a basil vinaigrette out of it. And then what he did with the carcasses of the fish and sold to, lazily made the fish emulsion out of the carcasses, you know? That’s fish emulsion as they used to fertilize houseplants. You can buy it at the store, you know, it sells decorative plants. Anyway, they were getting a hundred, they just didn’t bottle the fish emulsion, they just produced that name, we’re getting $200 a barrel for fish emulsion. There’s a lot of tons of value-added things you can do. I had a pretty big farm that was putting all their roots and shoots into barrels, and then the pig guy would come pick it up for a dollar 25 a pound, you know? It’s a little bit of money, but he was getting, you know, 50-pound barrels every once in a while and turning that back into money.

So, on that note, what are some of the more peculiar or different or strange or maybe less orthodox aquaponic programs that you guys have been involved with?
Speaker 1:
My memory is failing, just being careful with this tone right now. Well, one thing that doesn’t work is aeroponics. I mean, aeroponics works in hydroponics, but the solids will clog those emitters, those sprays, and I wouldn’t recommend aquaponics for aeroponics.
Speaker 2:
I’m running out of energy here.
Speaker 3:
Well, I think there’s a way around the aeroponics. My friend Pedro, actually your student also, do you remember Pedro Casas in Puerto Rico, Jim? He had a project, eCos, which was one of our success stories there, just south of San Juan. He adopted some A-frames all the way down one of his UVI troughs, and at the top, he used an aeroponic kind of misting system. Every day, they’d have to go by and walk through all 18 A-frames, or however many it was, and clean it out. But their systems grew mint and watercress, and he had some basil plants in there and Pok Choi, little bok choy plants. That vertical really increased the spacing on one of their troughs.
Speaker 1:
You know, something I don’t… when anybody comes to me with crazy ideas, well, sometimes I have them sign a confidentiality statement. What I can’t tell you one of the craziest ideas because I signed the confidentiality statement. They never did it. When they come to me with crazy ideas, I try to quickly talk them out of it, and most of the time, I refer them to taking an aquaponics course.
Speaker 3:
And now, well, you know, my business partner wasn’t managed just came out with a… I’m sure it’s the best book on aquaponics, a 400-page book called “The Commercial Aquaponics System.” Well, you say anything hasn’t bought it, you can go to his website and buy it. This website is aquaponics solution. Anyway, reading this book, because you’re a very articulate person, you learn at all, you get the update on everything except probably he doesn’t know some of the things you’ve done, Steven.
Speaker 1:
I don’t know. We’ve got a lack of the citizen, they’re not… you know, Jim, what I also get people come up with the most crazy ideas, you know. Aquaponics is already fascinating and crazy, and I usually tell people that you’re on your own. You know, you’re coming up with a new design that nobody’s proven, nobody’s run, and you… it’s not cookie-cutter like hydroponics is. I can go to Crop King and get a Dutch bucket tomato system and a manual on how to run the whole thing, and it kind of works. But aquaponics is a lot more… we say lazy man’s hydroponics, but as Jim said, there’s a lot of other complexities with fingerling rearing and supply that hydroponic growers don’t have.
Speaker 3:
So, yeah, no, that is actually one of the drawbacks of aquaponics because you’ve got to coordinate your… I mean, it’s easy to produce transplants. He thinks from seeding, it’s like three weeks could be transplants to put in your system. But when you deal with the fish, there’s a lot more complexity, and you’ve got to set up an assembly line kind of system that every single week you’re going to like harvest the fish tank, you’re going to… you know, you’re going to take fingerlings and stock their tank. When we had in the Virgin Islands, we had a good professional team, you know, four professionals, and we added like clockwork. When we harvested the lettuce at 6:00 in the morning, by 8 o’clock, the lettuce was harvested, by noon all the transplants were in, and then by the next day, the roots were already going through the net pots. We harvest the fish early in the morning, and by noon, the next batch of fingerlings were stocked in there. By that evening, they were feeding, and we did this for years and years and years, which actually kind of blew my mind that way that we did as well.
We have a question from Joe Pate, which I know Charlie knows. He says, “Hey guys, just want to say great show so far. Just wondering how your thoughts are on pre-dosing culture water with enough K and calcium to meet nutrient levels and then bringing the pH down with phosphoric acid.” And then I guess on that question, let me add to that, what do you guys consider the limit for phosphorus in aquaponics?
Speaker 1:
I don’t know. We always just got enough, so I don’t know what the limits are. There’s a ratio, this ratio there, it has to be… Charlie is the ratio between phosphorus and something else.
Speaker 3:
So, I personally, I found that calcium-phosphorus ratio, you want a three to one, and then you want a calcium to magnesium ratio of two to one. In general, that… there’s some things are different, you know, lettuce would be a little bit less than that. But in general, you stick to that, your crops are going to do great in aquaponics. And that’s just speaking kind of vaguely, you know, we kind of… what we are taught is really… we dealt with whatever this is going to be able to… basically, we were… yeah, we didn’t… you know, our system was designed for a farmer that would just throw fish feed in, you know, stock and follow our guideline, stock at the rate we say, you know, actually duplicate the UVI system, stocking rate, their planting rate. And as long as you can keep electricity going and disruption, cooking of their storms, or whatever, it just works. You know, it’s far more friendly. You don’t make it a scientist. You didn’t need to be a scientist to run the system, you know. There’s some basic understanding, just follow the guidelines.

Well, I think what was the first part of that question from Joe? Oh yeah.
Speaker 1:
So it says, um, or do your thoughts on producing culture water with enough calcium and potassium sabrine and then bringing the pH down with phosphoric acid? Well, prior to stocking that way you aren’t playing catch-up with adding a little every day and then you aren’t limited with your additions to by pH.
Speaker 2:
Prosper, they say using phosphoric acid to bring the pH down to add phosphorus to balance. Okay, well no, we never did any of that stuff. What we did is we would start the system and you would feed very minimally in the beginning and so that until the biofilters to become established, and then after they’re established, you would start stocking. You go to plant production, so we would only plant one-fourth of the system every week, and so it would be an additional four weeks before I was at full production. By that time, you were feeding at a pretty good rate.
Speaker 1:
Let me tell you what I’m recommending to people now that want to go commercial. We had, we have this is just, I haven’t tested this out or anything, but this is just a management practice. If you stock the fish, it’s one of the disadvantages about the products. If you have poor fishness and you want to stagger 18 weeks before you can get up to full production. So the first week at time zero, and you’re gonna stock one of those things. And since you have like twenty-nine thousand gallons and you’ve got a tank for small fingerlings, you’ve got a big dilution factor, so you can feed pretty much what goes fingerlings would want to eat. Although we recommend for the first month till the biofilters established that you measure ammonia and nitrite every day and nitrate occasionally. And when you see the ammonia nitrite go down and nitrate go up, then you know your biofilters established.
Speaker 2:
Well, at the end of that six weeks, then you start your next batch of fish. So you’re gonna be at half capacity. That’s when I would recommend that putting in your first graphic plants after six weeks if there’s crop where plants which would constitute 25% of the system. So that’s just kind of a rule. I don’t know if that’s absolutely optimal or whatever, but we don’t do, we don’t work on any pre-establishment.
Speaker 1:
I think if you work, I think what you’re talking about a small system here, they’re just really small system and you want to get going fast, but we never did that. But I think that what Joe is saying is very wise to jumpstart your system, you know. Joe, if you’re trying to get a quick establishment maybe for cash flow, maybe you could run the troughs almost like hydro for a little bit and then bring some of that nutrient in.
Speaker 2:
And he’s also saying if we add the, I think what he’s saying is if we add the potassium and the calcium maybe at in advance where there’s the two nutrients.
Speaker 3:
Steve, yeah, I think that in my opinion, the best way to do that, if that was your goal and say you had a brand new system and you needed to boost the numbers and you wanted to do this, and say you, and this is also the same would apply if you didn’t want to do it for that reason, but say you have a starting pH of 8.2, 8.4. You’d actually just take a bunch of dry ice. It’s dirt cheap. You can get it pretty much anywhere on the planet just about, and take your dry ice blocks, drop it in your aquaponics system before you actually throw any fish or bacteria or plants in the system. It’ll crash the pH through carbonic acid, and then you could actually buffer it back up with your calcium and potassium, bringing it back to the proper pH level without any need to actually use the phosphoric acid.
Speaker 2:
That’s very, that’s a very good idea because we started a lot of times we started the pH was eight. And so for the first several weeks, we couldn’t add any of our supplements, and because the pH is already too high, and our plants would suffer. So that’s a good, that’s a very good idea.
Speaker 3:
Yeah, we did, didn’t we have dry ice? I don’t know, but you can add dry ice in the book now. I think you do because they ship stuff in it all the time, so there’s probably a, there’s a…
Speaker 2:
So I got turned on to that dry ice pH down method by um, a bunch of koi guys that build koi ponds, and it was one of the cheapest ways for us when we, we’d have a koi pond I’d fill it up for the first time, and because of the sand or the rock or the tap water, it’s in the eights or you know somewhere in the eight pH range, and the Koi, at this expensive koi, I got 60 grand worth of koi sitting in my truck. I can’t put them in a pH as a whole point different. I’ll kill them. So I could use the dry ice. I can to the store, drop that in there, throw it in there, wait about two hours, it would all boil off, it would level out the pH in there, and then I could buffer it back up, and then you know by the end of the day, I could actually put the fish in and bring them pretty, you know, adjust the pH pretty freaking close, and that you know allowed me to do things much faster rather than waiting two or three days to actually get these fish in.
Speaker 2:
What one thing is what we’re talking about nutrients, you shouldn’t if you use a media system, you shouldn’t use limestone as your media because you’ve been too high of calcium levels in your system. A lot of oil in situations where the only gravel is from, you know, they find on the seashore and stuff like that, that’s all calcium carbonate, and then so you hear media’s all calcium carbonate and getting really high calcium limits.
Speaker 3:
Yeah, cool. By the way, Jim Rakosi, Joe Pate is a graduate student in Kentucky State under Jim Tidwell and Janelle Hager.
Speaker 2:
Yep, and he’s actually the, the gentleman that helped you, that the research project on the and paper on the lactobacillus increasing fish growth by 15%. He also did some research with aquaponics and hemp as a crop at Kentucky State.
Speaker 3:
Is there any value to him? I just had an inquiry about him. Is there any value? It’s not like unless you’re gonna do something really large-scale, doesn’t make sense because and growth, you can grow it in a field, and and it’s it’s kind of like growing wheat or beans, it’s just doesn’t have our corn, it doesn’t quite make sense in aquaponics, but you will get increased production of certain cannabinoids and terpenes.
Speaker 2:
But aren’t there some high CBD hemp plant that you grow as short plants full of oil seeds?
Speaker 3:
Yep, yeah, and that’s the reason why when you can grow acres and acres and acres of something, even if it’s much lower potency, your production is so much higher that it kind of swaps the need to do it on a smaller like even a greenhouse setting, you know. It for medical cannabis that makes sense, but for fueled hemp, it doesn’t unless you’re doing it for clones or something for even production, it doesn’t quite make sense.
Speaker 2:
Okay, Jim, I agree with Steve. Ken, I’m tapping into you. Have you heard any new things, and are you involved in any new projects?
Speaker 4:
Oh, last July, I was in South Africa in Stellenbosch University giving a short course and our workshop, a two-day workshop. And there was a man there from Pretoria that had a total paradigm shift of an aquaponic system, and he’s the good Easter girlie now in South Africa, you see. I can’t think of a, he’s got a special and crying, crying sure system or something like that he’s calling concert. And what he did is he’s actually got 600 square nones. God, he’s got, yeah, he’s a 500 square meters of plant growing area, and he buys, you can buy a canvas material that’s waterproof in South Africa. So his, he has these cells that are 14 meters by, is it six or eight meters wide? And anyway, he’s got a huge plant growing area for one system. And what he did, and I think he’s gonna run into trouble with that, as he made it the D ended Raceway. I don’t know if you know a B in the grace ways, it’s, yeah, the ends around it, and you put a baffle in the middle, and he put 14 cages in there that are about six cubic meters per cage and stocked 1,000 fish per cage. And every week, he draws the fish out of one of the cages and stocks it here, and he has a, he has a like a forty-two we grow out or something like that.
Speaker 4:
And okay, so this is a real paradigm shift because he’s producing like something like 20,000 pounds of fish in this thing, but he didn’t do it yet. He was just starting it up, and I told him, or one of the big problems he’s gonna have is getting the salads out of a lot of at the embrace way thing. And he has, he had some kind of a program that he looked at where the deposits would be made if you had a certain flow rate or drain line or green lines. I still don’t think that’s gonna do it because it’s just not gonna be that needs knocking, just there’s no phone bottom or anything, it’s gonna, he’s gonna get some of it out. And the other thing is those cages occupied every square inch of the of the tank, and so the fish are not free to roam around the thing get, and at all. And then he has, so I think he’s run into trouble with them. And then but that was a quite an original, other amazing thing that he did, and that is he’s, you can have temperatures as, as well as like zero in between. We’re talking about, I’m talking about centigrade now that I live in the rest of the world, we deal in centigrade. Image is going from zero to 40 degrees centigrade in like 40 degrees centigrade, it’s like over 100 degrees Fahrenheit, 0:32. And he went in before he built his system, he’s building for early systems, and before he did that, he buried this, what he calls as, did he put in greenhouse floors, the Hydra Tiger? I don’t come was that, yeah, hydrogen goes or heat lines not there, no, what is it?
Speaker 4:
When he put those, those, those pipes in the Florida House, hot subterranean heating and cooling undergrowth, radiant flooring, yeah, but there’s another name for the actual pipe anyway, against pecks wood. Okay, well, he went to work in it, in a backhaul, and he put, he dug trenches all around his facility. They’re worth, I believe there were three meters deep, that’s like about nine feet, and and he got at that depth, the temperature remains constant year-round. And by using heat exchangers, even though he had this incredible fluctuation and sphere temperatures, by using heat exchangers, he was able to maintain his water temperature twenty-two point seven degrees centigrade, which is roughly what about 70 degrees or something like then there, no, that’s right. Okay, so he had, so he’s geothermal heat, they didn’t, he didn’t have a deal, he just went very deep into the ground where the temperature doesn’t fluctuate, even though you could be freezing outside or over a hundred degrees and boiling, and he used that temperature to keep his water temperature at a constant temperature year-round. I think he’s, he had some really good success with the plants. I mean, I saw some of the plants in there, but he was just starting up, and I think he’s gonna run into trouble with solids getting this outside of the fish tank.

Speaker 1: Jim
Well, Jim, I’ve seen the systems—not quite the DD tanks—and I’m sure everybody can look it up, but it basically takes a rectangular tank and you put a baffle down the middle and you curve up the corners and you move the water, so it gets a circular motion out of a rectangular tank. I’m seeing some cages stacked in there. If those guys could lose some fish and have some fish on the outside of the cages swimming up and down and grazing the walls, that would help for sure.
Speaker 2:
I think so too because these cages were, I think, flush to the bottom and they’re adjacent, right adjacent to each other. And he had—oh, here’s another thing—he had his inflowing water, he had an inflow line under each cage with fresh water coming up. It wasn’t like going in at one end and then by the time it got around to his really bad water quality, all the influent water was coming up at 14 separate points right under each cage.
Speaker 1: Jim
It’s a visit he did this all very, very cheap. He had these wire meshes for the—you know, wire mesh with the liner.
Speaker 2:
Yeah, absolutely. And I need yetis binky range canvas tanks that you know, present for the growth for the plants. I thought it’s gold meters—I mean, 500 square meters, there were five thousand square feet of plant growing area and one fish tank, one fish tank in its staggered, it’s in cages, it’s easy to harvest. It was, I considered, a paradigm shift. But I think, you know, run into some problems, and but I think that something like that should be pursued here too.
Speaker 3:
Are you saying this is a system that’s just coming online?
Speaker 2:
Yeah, he’s going to do four of these, and the slides he showed me where he shared a lot of information after the conference, and then he supplied. But I don’t—I don’t think he was up to capacity, and so I don’t think he—he was brand new to fish culture, so I work, but I don’t think he realizes what the practical aspects are gonna run into. But he’s already teaching, it’s already teaching right away. I just saw pictures recently teaching and ready. Please, everybody, nobody in South Africa cared a lot about what I have to say, that all in just in a way he was to me.
Speaker 4:
Yeah, you guys, um, that’s something that if anybody’s still listening, that I saw a presentation recently, as I was listening earlier, Dr. Rakosi mentioned Dr. Merle Jenson. And so I watched a video—he’s a great speaker, man, what a great entertainer. So if you go on YouTube and look at Merle Jenson, if anybody doesn’t know, if you go on YouTube and look up the CEAC, Controlled Environment Agriculture Center at University of Arizona, there’s a wealth of resources of videos and all kinds of topics in that field of CEA. Dr. Merle Jenson was talking about consulting, and some of us try to consult, some of us don’t know anything about consulting yet, but maybe you should. But he talked about his history, and I want to honor having Jim Rakosi and thanks Steve for putting it together because these guys have made a history. He has a whole line of experience to learn from and to teach people from all the mistakes as well as the good stuff. And so Merle was stressing that. So it’s really hard for people, young without experience, to be representing our industry as a consultant. So beware. I don’t think many of your listeners are using consultants. Most of your listeners are tinkerers, are going to do it themselves, and that’s what Jim and I taught for the whole time I was with him. I still teach that. I taught a class recently with Steve. We inspire you to build your own system. We teach you the principles, and we can help with some design work, but really, you’re on your own, like I was saying earlier, and improve us, you know, do a good system and show it off and boast. So I look forward to that. But thanks again, Jim, for being here and sharing with us.
Speaker 1: Jim
Well, yeah, you know, I mean, you’ve rejuvenated me here. I haven’t been talking about aquaponics very much because I have a condo in Florida, so I come back, I come once a year in April.
Speaker 4:
That’s good. We’ll do this again a year from now. People want to find out more about what you do, how would they find out? Is there a place you can direct them, a website?
Speaker 1: Jim
Our website is called the Aquaponics Doctors.
Speaker 4:
Wonderful, that’s—
Speaker 1: Jim
Wasn’t Leonard in me.
Speaker 4:
Wonderful, that’s awesome. I’ll make sure I get that in the description of the video so that people can just click the link and get right to you.
Speaker 1: Jim
Oh, thanks, and we really appreciate your toast. Those were awesome. [Music]
Speaker 4:
Thank you so much. Thank you so much. Okay, thank you. Take care.
Speaker 5:
Okay, Baba, ain’t like we always say, you guys, if your systems in balance and you’ve taken care of what you’re supposed to take care of, you should be able to sleep well tonight. So I hope everybody sleeps well. [Music]
Speaker 4:
Thank you. Awesome, that was really cool. Dr. Faust, if you’re still there, you had something to mention on the shrimp there, and then I actually had two questions for you if you’re still there. From—we had an in-chat. You might have a—he’s still on mute, so if he’s not there, if not, we’ll see if he comes back. How you guys doing, Hog Master and Roger? What’s new with you guys?
Speaker 6: Hog Master
What’s new with you, Hog? Just trying to sell everything and get moved, buddy.
Speaker 7: Roger
Doing this across several state lines, moving is gonna be an adventure for sure. But I got a lot of crap and don’t need half of it, so I’m either gonna pitch it or sell it.
Speaker 6: Hog Master
Mm-hmm, start fresh. It’s gonna be awesome.
Speaker 7: Roger
Yeah, there you go.
Speaker 4:
Are you back now?
Speaker 8: Dr. Faust
Yeah, without my out of my swim spa while I was listening to me.
Speaker 4:
Joey, that’s awesome. Obviously, you had something to chime in about the shrimp door for years, you know.
Speaker 8: Dr. Faust
It’s not on the scale it should be because it’s just hard to get people to drop these things, but we had some innovators in shrimp in Ecuador, and they got into using our Ion 14 product, which is what I developed in Hawaii because of the silicic acid and activated humic substances, you know, limiting factors in soils, etc. And we were selling that product in Ecuador because it’s, you know, volcanic soils like Hawaii, Ecuador, and there’s that specific limiting factors in the soil. Then our customer, who’s sort of a broker, just dealer down there, he had some customers that wanted a silica source for shrimp. These are outside shrimp ponds that they made. Their system down there’s like dirt ponds, you might say. Anyway, so they started using our Ion 14, just throwing it in the water, and the problem in shrimp is this white puffs, white spot disease, and other diseases, things like that, under high density. And with the humic, of course, it darkens the water, which helps protect against UVB, especially at that altitude. Well, this wasn’t necessarily that high altitude, but it protects, you know, it gives us a degree of disease resistance, not just because of colors the water, darkens water, but because of the polyphenols, carboxylic that activate resistance pathways. And, but in general, it’s just like chickens, for what we’re doing with—well, chickens is a probably a better example than cows—but just in general, better feed conversion, faster growth, more vigor, you know. So humic substances, I mean, at least the functional group part, you know, that’s really just as crucial, maybe more crucial. Not, but it follows a general rule of thumb from pretty most, most all animals. Provides with, like in kids, it’s 14% because increased feed conversion, and chickens about the same, little less. It doesn’t really matter, but yeah, that’s our experience in Ecuador. And then we had people using it on crayfish in Louisiana in big, big operations, you know, where they put it on rice first, and then, and these are TM7, Ion 14, and they flood the paddy. That culture, though, the state shut them down because our products not improved, not approved, right? And the problem, problem is with humic substances in the US, and why we act as we sell in Europe and South America, because in the US, the FDA doesn’t approve it as a key ingredient. See, they’ve been holding back for years, preventing it from being utilized because it effectively replaces antibiotics and hormones in livestock. B, and in Holland, Europe, know that they, you know, considered that’s what they’re looking for, something can replace biotics and hormones. So that’s what holds it back to me. Yes, there’s nothing to stop people from using it. We just can’t believe it. Aquaculture attitude, or like chicken feed. I wasn’t aware about that regulatory problem organization, probably.
Speaker 4:
Create association, they hired lobbyists in DC, through, you know, they won’t even accept a grass petition, that’s generally regarded as safe, and that’s the, you know, to use it, and the petition. Whereas in Europe, it’s approved as a veterinary supplement. Yes, there’s no restrictions in or against veterinary Randy, but the rest of the US, no, you can use it. They’re not gonna stop you. You can’t promote it. You can’t believe what we sell it to some of our other products to hog producers in Iowa, you know, they just learned that it works, and they use it. So that’s the situation there, but it has huge potential, absolutely.
Speaker 4:
Yeah, friendly an issue for US producers. Yet another question, this is a Dr. Faust, what are the differences between chemical extraction kelp extract and cold-pressed kelp extract?
Speaker 8: Dr. Faust
Similar to how you solubilize humic substances, or you knock the pH down. It’s like how you make soap, it’s a saponification reaction. So it’s not much different than what you do. So we take the fat-insoluble stuff, and you curate it’s soluble by saponification, or the fat, like an emulsion. Whereas, yeah, you could do—you see, because the—but I don’t know in terms of getting all the goodies. I’m not sure about cold-pressed, but there were some good products on the market. You get the cytokinins that way, whether you’re getting with minerals. Kelp is a good source of a whole range of minerals and humic substances. You just count products, you’ll find humic substances. But, you know, there, sea plants, and sea is a good source. All the humic acids lining up in the sea, and so, you know, kelp takes it up. So you have a certain amount of that in there. So just whatever is practical. I mean, whatever it may work. Most of the junk on the market is gonna be your kelp. I draw a—you’re using hydroxide solubilization. I remember one, the one in Maine, I forget, but yeah, that was the deal on that. Yeah, that was nearly always a liquid product. Yeah, I used to buy it from a guy at the Waldport, Maine. I could get the name, but it was a cold-pressed, it was a liquid, but it was very unstable. You know, you put it in your boiler house, and the five-gallon pails would swell up and roll over, come off dancing. Don’t you know, it was a good product, but it just didn’t have any shelf life. And we get the nice dry max, you dropped kelp from Norway, and it’s, you know, you can keep that for years. Make the solution when you need it and use it right away because this stuff is very susceptible to microbial decomposition, big-time. So you make up a tub solution, you gotta use it at least.
Speaker 4:
So that’s, imagine, you know, the technique.
Speaker 8: Dr. Faust
Another question is, what about grape pumice, pressing remains as a source for humic acid? I use horsetail extract

Speaker 1:
“Well, let me jump in here ’cause Steve jumped out of inside serve up—up—sorry about that. I was just refilling my glass here. Uh, what are there to five different tendons, okay, I’m just gonna say it’s definitely a rabbit hole you can go down some day.”
Speaker 2:
“And what was his audio recording a little talk, but he’s written a couple of books on the subject. I got all his books. He was a professor, I think at Georgia Tech. But if you look at the humic acid literature, you know, references to Tan, Dr. Pan, T-A-N, Chinese or more, he gets into the nitty-gritty.”
Speaker 1:
“And he’s put together, well, it’s kind of a source book on the chemistry, you know. This is something that they discussed at these meetings. Language was time might fall asleep; they don’t want all the chemists to start really getting into the arcane chemistry. It’s sleepy time for me, you know. I’m looking for really practical aspects of these things.”
Speaker 2:
“Oh no, no, we had another question. As I know, some organic acids have anti-nutritional factors in fish. Are there any anti-nutritional factors alluded to fullvic or humic acids that you’re aware of? I know that you, different personally, I know that you spoke about there’s a bell curve on the humics and fulvics. Nor would I imagine that would apply to other organisms aside from plants.”
Speaker 1:
“Yes, and that’s the kind of stuff that actually reduces plant growth, seed germination. So that’s the stuff that has all these methylene, you know, it’s like nicotine. So there’s definitely some negatives. There’s a range of negative compounds that can be—I mean, these things vary like gigantic. But the ones produced in nature, let’s say, you know, like in the forest or an ombrotrophic swamp or something like that, it’s a pretty balanced system. But again, it depends on what the—if it’s humic substances made from saltwater sedge or pine, you know, it can be negative, it can be toxic.”
Speaker 2:
“You know, if it’s made from broadleaf trees, oaks, cypress, and that kind of hardwood trees, especially from the tropics, that’s the kind of the good stuff.”
Speaker 1:
“Yeah, so it really is dependent on what the plants are, you know, where the feed material that started the end of it. None other workers and rich hardwood trees and nitrogen-fixing trees put in some rich humic substances which produce a rich watershed. It’s all tied together.”
Speaker 2:
“There you go, throw some something like coal in there, you know. A lot of it is whether it’s aerobic or anaerobic, like anything. Like if you make compost and it goes anaerobic on you, there’s just smell, you know, hydrogen sulfide, all that smells like rotten eggs because you let it go anaerobic, used up all the oxygen.”
Speaker 1:
“Okay, so now it’s producing stuff that, if a plant root touches it, that root stops growing. That’s it. And if you use it for mushroom production, forget it, you know, it kills the mycelium. So the substances that are formed, the composition under lack of air, with no oxygen or air, are bad news. So, you know, these things have to form, you know, in an environment where there is oxygen and not like those. If they’re forming anaerobically, you get the high oxygen fulvic, which is, you know, very high oxygen. And if it’s deep, you get cold, you get, you know, the methylene groups, the stinky higher sulfides, toxic compounds. So it’s pretty much organic matter can go one way or the other, Anya, whether they are only granted a little bit. So that’s the main key there, you know, if that happens right, the good thing.”
Speaker 2:
“But try though the water that comes out of a coal mine, see how that one goes through you, you know. Check those streams out; there’s not a living thing in the water, but it’s all like humic substances. So, derived from plants, myeloma kill this barium, the other one makes it rich.”
Speaker 1:
“Yeah, because like I’d say, it’s just got to be a pretty narrow range to be, you know, optimum results. So that’s T color, like ice tea color, and if it starts getting darker than that, so that’s—that’s about it, you know. I think everybody’s seen those kinds of streams in Kansas, but I remember, you know, being up in the mountains as a kid and noting that where we really gave with some good trout fishing up in the Appalachian Mountains where we had that tea-colored water. And I didn’t know what was, you know, I just liked fishing. There’s a correlation there.”
Speaker 2:
“Well, that’s about it. It’s just nature. Nature doesn’t do anything, but if you mosey off your agriculture, then you think about doing some compost, vermicompost, humic substances. But like I work with converting biomass with Pleurotus ostreatus into a high-protein fish feed. That was something that I did, and when I worked out a mechanical method doing mail quantities, so that was the big problem in aquaculture was the cost of the feed. They’ll be a few, so they don’t like you say little ties together because those same fungi producing substances.”

Oh yeah, that was great. I think I pretty much appreciate you coming back on the show again this week and joining us again. Yeah, it brings it all back. You know, we work by geothermal, but it has to do with all the things that make up a good business. [Music] Alright, well, I think we’ll wrap things up. We’re a little bit longer than usual already, so I really appreciate everyone for coming out on the show, and I really again big thanks to Dr. Rakosi for joining us and all the work he’s done to help us get to the point where we can even host this show. So, I very much appreciate him and all of his work he’s done, as well as Charlie for chipping in and joining us, and Dr. Faustus again for coming back. Any previous guest is always welcome on the show, and thanks a lot for coming back again and hanging out with us and sharing your knowledge as well. So thanks, everyone, and we’ll be back again next week. And if they want to reach out, I’ll make sure…
Host Continues:
…and then talking starts with aquaponics out here. So, we kind of decided today where we’re going to place it finally. So that’s because I’ve had 10 different ideas, you know. It’s one of those things. Well, one of the things is it’s got to be in proximity to the well, that makes sense, you know, like a straight line. Basically, I’m gonna put it right next to the driveway, the main big driveway. I’m gonna put it five feet off of that, and I’m just gonna start with a 24 by 30. And I like what, uh, I think it was Charlie, was it Charlie or was it… I think it was Charlie, talking about how people use greenhouses when they don’t need them. And I thought that was interesting because when I first started, I kind of had a greenhouse thing, an area I built, you know. Of course, I had all these plants started, you know. So, I just did. I built my system before I built my greenhouse, you know. Then I built a small greenhouse. Well, actually, I had a small greenhouse, and I was in the desert transitioning from like a 12 by 16 to a 48 by 30, you know. And I outfitted it with all the plumbing and got the reservoirs and all that, and then I started putting plants in there. In the first year, I really didn’t have plastic a lot when I started out. It was such nice weather, you know. I just basically followed the directions for outdoor hydroponics and all where you increased your mix by 15%, you know, the salinity of your mix by 15 percent of training, you know. And that was a dog in that came from South Africa, you know, trials and farms, well how they did in South Africa. So, I always felt like it’s hotter there, and there’s bigger bugs, and you know, you know all around. But if they can do it there, you could do it here in America. And it’s very inexpensive along the ways they do it too. And I can see where you can add, you can add to aquaponics. Well, I’m just seeing so many ways that you could, you know. I mean, just, I’ve just seen so many ways that things are meshing together where I almost question someone like you. I love it. It came up tonight. I’ve been questioning some of the systems and things I’ve been hearing people say they’re doing, whether it’s really hydroponics or aquaponics. So, I thought that was great when Dr. James brought that up tonight, you know. A lot of people were doing things, and they’re kind of not really aquaponics. Yeah, but I think that’s where we’re at. It’s just like to do a roots on you. Well, there you go. There’s another argument. Well, soil is an aquaponics. Oh, you know, I mean, it’s a, you know, I mean, I see what you got, but you know, you can make an argument that it’s not pure aquaponics. I mean, you know, just like, you know, so you’re using hydroponic methods for aquaponics, right? I mean, I mean, the system kind of started with that, wouldn’t you say? I mean, I didn’t mean to draw this out long either. It’s just, wow, I just, it just came out of my head, you know. Oh no, so you’re just by having into words, and you’re getting the benefits of those micro microbes, that’s all. But aquaponics, poor definition, doesn’t have to be soilless. For example, wicking beds, you go root crops, onions, potatoes, carrots, you have to have some kind of soil medium, be it Kovac or soil, you know. It doesn’t get one on the other to get them to grow proper. So, you wanna tell everyone if you’re in Colorado, I will be at the big Rose Cup on Saturday, so I will see you guys there. I did see a couple of people on chat who will be there. I’m super stoked to meet y’all, and yeah, if you’re in Colorado, definitely check it out. Do grows calm /dg c-cup, and you can email them, and they’ll send you a link to get your as invite only because of the rules in Colorado, so you do have to get them to send you an invite link, but definitely come out, support the show. They’re great guys. They also have a very awesome podcast twice a day at 4:20 a.m. at 4:20 p.m. Well, do grouse show, and yeah, though they’ll be doing that. We have Ouroboros farms calm. You can check out all the classes for us of the year. Me and Charlie and Ken will be teaching another class or two of the commercial class this year, I believe one is in May, and the next one I forget when the last one is for the year, and then we have some other classes coming up as well. Check out the schedule on there, and oh, we’re also working on a really cool event. Can’t talk more on it until we get the date settled, but we have a really cool aquaponic / cannabis event coming up that’s going to be a week long, and it’s gonna bring in some of the coolest people that you guys would ever want to learn from and give you kind of a hardcore experience, and they’ll be way different than anything you guys have ever done before. It’s gonna be revealing some, and I can’t talk anything beyond just a little bit of its teaser because we’re still nailing down specifics and dates and exactly who’s going to show up, but definitely want a plant to see. Definitely look at sometime in July or August to keep your week free for us, and I think you’ll be happy you did so. And that’ll be out here in California, so stay tuned. Oh yeah, yeah, it puts a big smile on my face with the people that I’ve already agreed, and we’re trying to nail down everyone and then end date, so you guys are gonna [ __ ] love this. If you’re a vegetable producer or cannabis producer, you’re gonna really like it. And then if you guys are in the Bay Area for 4/20, I haven’t 100% decided. I know there’s a cool event going on in San Francisco. You can shoot me an email if you guys are around and want to get together, and we’ll coordinate on that. You could shoot me an email potent products at, and yeah, there’s a big event up in San Fran. I think I might pop in and come hang out with some homies up there. If not, if you guys have a cool event going on, maybe I’ll wander over there with a couple of goodies as well. So yeah, I think we’ll wrap it up again. Check out my youtube channel potent tonics. Real great info. I’m gonna start putting up some more content. Will have some DGC footage from the weekend, a bunch of cool videos hanging out, chilling with everybody out there. I know tomorrow night is the grow to thing. I’m gonna hopefully be trying to hang out there. I don’t know what’s going on. I think it’s at the same place where the DDC cup is. I heard some rumors on know if that’s true or not though. We’ll find out tomorrow. Yeah, definitely look forward to this weekend and hanging out with a bunch of our listeners and getting really high. So check it out, and I’ll see you guys next week. Take care. Oh, oh, oh, almost forgot. I got a really cool announcement for next week. I almost forgot. Big shout-out to Mr. Greenjeans who helped Clint get this opportunity for the speaker for next week. Now tentatively, he might have to change weeks last minute. We have Gypsy Nirvana on next week. Gypsy Nirvana, if you’re a seed and a breeder, is a legend. Gypsy Nirvana has been fighting extradition from Nina, okay, by the US government for years, and he just won his case against extradition a couple of days ago, and he’s gonna talk to us all about his breeding experience, his battle at the DEA, his battle at the US government, and the trials and tribulations of being a clandestine seed grower and selling your seeds across the planet by someone that is world-renowned and one of the biggest names as far as the internet goes on that, and one of the biggest names as far as people that has fought the US government one is a pretty big precedent for the movement and in medical marijuana. Yep, so that’ll be really cool. Tentatively, we’ll have him on. We might have to reschedule. He’s joining us from the UK, which will be very late his time. That’s the reason why we’ve had problems getting Jorge Cervantes on is because it’s 3:30 in the morning in Spain, so we’re trying to coordinate a time where he’s not in Spain to get him on the show. So if I have been playing tags with him by email and just kind of waiting for him to have a time when he’s in a reasonable time zone for us, so that is still happening. We have a couple of other cool guests that we got lined up. I’m not even gonna rattle off a list right now, but we got a bunch of cool people, and yeah, so thanks a lot for everyone watching, and we’ll see you guys next week. Sorry for babbling so. Cheers.