Tuesday, August 20, 2013

Aquaponic System Final Design

So, here’s the floor plan. As you can see, it is 22.4m long and 6.55m wide. Some system details are as follows:

Aquaponics, ækwəˈpɒnɨks, pisciponics
Aquaponics, ækwəˈpɒnɨks, pisciponics

  • Rearing Tank — The rearing tank will hold roughly 9.5m3 of water. I rounded the ends so the stupid fish don’t get bloody noses all the time. The tank will be stocked every 4 weeks with 120 fish. There will be 6 cohorts of fish aged 4 weeks apart at all times. I will separate the cohorts with suitably sized netting. The position of these divisions will be adjustable in accordance with the growth rate of any given cohort. Harvesting will be done weekly, 30 fish at a time. The outside of the tank facing south will be painted black and exposed to the sun.
  • Hydroponic Tanks — There will be 4 hydroponic tanks. Each will be 12m long and 1.2 meters wide. At a water depth of 30cm, each tank will hold roughly 4.32m3. Plants will be put in net pots which are inserted into holes in Styrofoam boards (1.2m x 0.6m) and dangle their roots happily in the nutrient rich water.
  • Clarifier/Filter/Degassing Units — Each hydroponic tank will get its own set of these highly important if simply designed contraptions. A clarifier, otherwise known as a swirl filter and other such names, removes the lumpier pieces of fish waste. I intend to use 200l plastic barrels. The filter is just another smaller barrel that’s got an armload of orchard netting in it to which the finer solids will be instructed to attach themselves in an orderly fashion.  The degassing tank is another small barrel with a few air stones in it to help remove carbon dioxide, methane, and such.
  • Pump — I’ve purchased a Reef Octopus recirculation pump which will push 7,000l per hour while consuming a frugal 88W. This is roughly 1/4 of the flow rate that the UVI system uses.
  • Air Pumps — I’ve purchased 5 Hailea air pumps. Each would push 60l of air if only I were at sea level instead of 1,200m. They are also frugal, using 55W each. Each hydroponic tank will have its own air pump. Ten of the 12 diffusion nozzles fitted to an air pump will go to air stones spaced equally along the bottom of the respective hydroponic tank. The other two will be fed to the degassing tank. The 5th air pump will be devoted to keeping the fish bubbly and happy.
  • Sump — The sump is just a 1.2m round concrete ring set in the ground at a lower height than the rest of the system. The pump will reside here and replace the water that has flowed by gravity from the rearing tanks through the other system components.  There will be certain losses due to evaporation, plant uptake, leaks, etc. Depending on the water temperature, this loss will be replaced by either hot water produced in a solar water heater (a nice name for a couple of 200l barrels painted black, facing the sun, and enclosed/insulated) or ambient temperature water from a rain barrel. This is also the place where additives such as hydrated lime are gradually added if necessary to raise the PH.
  • Total Water Volume — About 30m3
  • Total Growing Area — 55 to 57.6m2
  • Greenhouse Footprint — 147m2