Module 9 – Summary

Summary

Think of building an iAVs as being like baking a cake.

Recipes are guidelines that allow home cooks to produce a satisying result – without the need to acquire the knowledge and skills that would otherwise be required if you did not have the recipe.  A recipe is a “quick start up guide” – a means of being able to produce a result with a minimum of fuss.  To that end. we’ve provided you with the iAVs Recipe for Success.

If you’re new to iAVs (and everybody is), you are strongly advised to use this recipe as your starting point.  As you gain knowledge and skills, you will eventually be able to vary the process….but you’ll be doing so from a position of experience…..and there really is no substitute for that experience.

The Equipment and Ingredients that we’ve stipulated are essential to iAVs.  Without sand, it’s not iAVs…..and without furrows, it’s not iAVS…..just as a chocolate cake without the chocolate is not a chocolate cake.  Every aspect of the iAVs is there by design.

OK…so what if you live someplace, for example, where tilapia are a prohibited species…or where it would be cost-prohibitive to maintain water temperatures ten degrees higher than the ambient air temperature – for months on end?  We acknowledge that there are situations where it is simply not possible to comply with our recommended Operating Instructions. In the examples we cited, a substitute species will need to be identified – or a controlled environment will be necessary.  These deviations from the recipe can be accommodated with our help.

The iAVs Recipe

• Essential Equipment:
  • Fish tank
  • Sand Bio-filters, aka ‘Grow-beds’ (start with one filter per fish tank)
  • Water pump – capable of emptying the tank in an hour – at the rated head.
  • Air pump and air stones (ceramic stones best)
  • Timer – digital recycling
• Essential Ingredients:
  • Sand – as per specification.
  • Furrows – as prescribed.
  • Water  – potable – and clean air
  • Feed  – use a formulated ration
  • Light  – natural sunlight is best
  • Fish  – species selection is a factor
  • Plants –  fruit bearing and/or of mixed ‘type’ (Families)
• Instructions – highly recommended
  • 1:2 fish tank volume to sand bio-filter ratio (for the number of fish indicated below, and with large fruiting plants)
  • Water – adjust pH to 6.4 (plus or minus 0.4) – rainwater is usually best.
  • Provide at least 12 hours of light per day – more is better – plant species-dependent.
  • Start off with 80 to 100 x 15g fish per 1000 litres.  (grown to 250 to 300 g, then start to cull larger fish)
  • Ambient air temperature – plant species/season-dependent in the 15oC – 35oC range.
  • Grow a mixture of leafy greens, and legumes but have at least 50% of the growing area in fruit-bearing crops.
  • Feed at least twice per day – last feed not later than 2:00pm.  (earlier in the tropics or hemispheric winter)
  • Irrigation volume and frequency – designed to 2 tank exchanges per day – two hours of pumping – work on 8 cycles per day to establish the duration of each flood cycle.
  • Irrigation volumes and frequency  –
    • pump 25 to 30% of tank volume (15-20 min ON) once every 2 hours starting at dawn, and finishing at dusk.
    • complete one full tank exchange (3-4 ON cycles) after the early morning fish feeding
    • complete another full tank exchange after the mid-day fish feeding and before dark.
  • Water Temperature –– 25oC – 30oC.

In essence, we’re saying that, if you follow the above ‘recipe’, you can anticipate the same enviable outcomes as those demonstrated by Mark McMurtry in his research trials – and subsequently by Boone Mora in his successful USDA-sponsored commercial trial.  Indeed, since Mark never set out to optimise anything (that wasn’t the purpose of the trials), it’s quite possible that you will exceed his outcomes.