Peak Proof Aquaponics in Zone 5?

So I have been completely obsessing over this Aquaponics idea and I want to put some of the ideas on paper and hopefully spur some additional inputs to my thinking.  Though still definitely in the experimental stage, the skills needed to grow fish in a recirculating tank system are getting dialed in to a level that fish loses are dropping to the near zero range in well managed operations.  Where I see the next stage of design sophistication will be in making the system Peak Proof by dialing out the fossil fuel inputs to make the energy inputs as sustainable as the food system.
And those fuel inputs are sizable.  What the Growing Power system is doing is essentially keeping 10,000 gallons of water at 78-82 degrees every hour, every day, year round.  In a Hoop House.  In Wisconsin.  Given the BTU needs of keeping that much water 80 degrees during a 4 month Winter, I don’t know of a feasible way around the NG heater at this point.  Preheating the water seem to be the only workable option, and that system would then handle 100% of the heating 8-9 months of the year.  
Probably system components:
  • Solar Water heating with thermosyphon pumping
  • Small Wind Turbine charging batteries (DC water pumps; small inverter for lights) and sized to dump excess into a heating element in a tank before the boiler.
  • Running water lines through Hot Compost Piles which are also located within the greenhouse for theoretical 100% thermal efficiency.  Currently looking for BTU figures for compost piles.
  • Modified Hoop House with insulated North Wall
  • Modified Hoop House with multiple layers of “inflated” plastic for better R values
  • Dream system based on the BioShelter of the New Alchemists with passive solar elements, built into a hill.  This system works best built onto an living structure.  This might be the only Peak Proof Aquaponics system using Tilapia.
  • Ditching the Tilapia and switching to Lake Perch.  The backup system for the NG heating could then, in theory, supply 100% of the heat, reducing winter water temps to the 50-65 range.  Perch can survive being frozen solid in Wisconsin ponds…
The last piece is probably the Sustainable Option.  But the lose in harvest would be severe.  Perch stocking rates are already a third of Tilapia, and they will not grow much in water under 65 degrees.  Furthermore, Tilapia are omnivores, allowing you to grow much of the food in duckweed and water lettuce, and also giving you a better place to put your now marketable greens than the compost pile.  Finally, Tilapia are easy to breed in tanks, but a Perch system puts you into dependance on the DNR.   Other options would be using a methane digester to make your own Bio-Gas, or a biomass based boiler.  Either of these gets expensive right quick.
Partnering Aquaponics next to heat intensive industries make allot of sense, but most small landowners do not have access to that.
Still, the system is still brilliant and I know there are ways to make it work off grid.  
Please shoot me links, ideas, comments, and resources!

10 Responses

  1. Well assuming you can get tilapia/perch broods cycling in the right sort of time period you could reduce your heating costs by keeping the tilapia broodstock in aquaria in the house – if memory serves they will lay eggs fairly regularly once paired.

    In the winter months you get rid of them and as the water starts to heat up you go for it. In winter you could keep the system circling with a brood of lake perch…..

  2. I have been giving that alot of thought. The issue is that, to my rudimentary understanding, it takes Tilapia at least 60 weeks to reach harvest size. To keep them out of the Hoop House in the Winter, you could perhaps start them in a much smaller, indoor, tank as 7000 fry will take up less room, and then graduate them out to the Hoop House come Spring.

    Perch take even longer to hit market size, but it may be possible to do a rotating system between two houses where Perch start in one after a Tilapia harvest, while the House that previous Perch had been in lies dormant for the winter and the Tilapia Fry are in an internal heated tank. I would ned to know alot more about the systems of this by taking one of growing Power’s seminars at the least.

    Thanks for your thoughts!

  3. Ah. I’ve seen figures for tilapia reaching a decent harvest size much quicker 6-8 months but then I guess that depends upon any number of things including how you define harvest size!

    I don’t know anything about lake perch but I’d have thought there are potentially a number of other options for a small system grower to exploit as niches (eg different cichlids including other tilapia, different carp species, etc etc). These are exciting times for food production and I can see aquaponics being big in the future.

    love the blog btw. I found you through Gardenrant.

  4. 6-8 months might be a hormonally modified all male brood fed on commercial feed-both of which would increase growth rates. The Growing Power system is more wholistic, but has downsides in the speed of harvest and total yield. I have not seen anything for various Carp species (they need a new name to be better marketable!) but one would think that they would have similar low oxygen/high stocking rate ability as tiliapia.
    I absolutely agree-even without the new innovations, the communication via internet of the myriad food producers in the world makes this a great time to be growing!
    Thanks for visiting!

  5. Of course the other thing I forgot to mention is do we need the fish component of aquaponics to relate solely to food? Controlled indoor but unheated production of small broods of (for example) decentish fancy goldfish ($5 a pop retail) or paradisefish ($3.50) could add a little profit margin (probably not much) as opposed to food if someone wanted to try very small scale home aquaponics. Or to put it another way ornamental fish farms could add to their robustness by producing delicious food plants as well as ornamental fish.

  6. I would second the idea of growing ornimental fish.

    I am coming from a aqurium background, and I am looking at doing a very small scale in-house ornimantal fish tank and hydroponic herb garden.

    The hardest part is the down-scaling of these systems and organic food sources for the fish.

    Another idea would be to split the system and do a warm and cool system during the winter months. 1 greenhouse gets activly heated for warm weather crops, thus warm water fish, and the other you let cool down some and run your cold hardy crops and colder tolerance fish.

    A split system would give you more redundancy anyhow. What happens if the water becomes contaminated, a pipe connection comes loose, etc, while your away for a day?

  7. We started at the other end of the scale with very small units at Portable Farms. Even in the 6 ft x 8 ft units here in Southern California we insulated the 100 gallon fish tanks and the 20 gallon settling tank. Two 150 watt aquarium heaters keep up to 225 gallons of water at 85 degrees even when the air temperate outside is 42 degrees.

    I realize that we get more sunshine here, and our systems can easily be solar powered even with the heaters running all the time. Our larger units 10 x 20 and 20 x 60 can be powered by fairly small solar energy systems.

  8. I’ve been lurking for a few weeks- love the site. I wonder about waste from the Tilapia (guts, bones, etc) Would it be fed back to the fish? There is a gator farm in Southern Colorado that started with aquaculture, and brought in alligators to eat the waste. Now they are a tourist trap, and sell leather and exotic plants. There’s some function stacking for you. They have a hotspring for their heating needs.

  9. Thanks for commenting Susan! We do not intend to process the Tilapia on site – that entails a slew of regulatory hurdles to jump through as well as separate FDA approved “facilities” for turning fish into meat.

    Feeding it back to the fish would not be wise for two reasons in this case – the first is that cannibalism is rarely wise due to the feedback loops that diseases can form. The second is that Tilapia are herbivores and would likely turn their nose up at their ground up brethren.

    That said, closing the resource loop is something we have discussed. Several options present themselves if we were able to reclaim the guts from our customers: methane production from the carcasses, pelletizing them into a fish meal fertilizer, or perhaps as a food for carnivorous fish like perch. The former two are my preferred options.

    Geothermal is a great way to heat an operation! Thanks for reading!

  10. Great article & comments. I’ve had a couple of thoughts about heating and sustainable food sources.
    re Heating – the Earthship approach could be used for your Tilapia farm? . This could be boosted using compost in various ways, as you’ve mentioned (like Jean Pain) and potentially, water heated through black piping coiled along a sheltered sunny position, or air heated through sealed units placed outside the greenhouse and ‘plumbed’ in, to be turned off when the greenhouse is warm enough. These units would be on the winter sun side and as warm air rises, wouldn’t require electricity.

    re Sustainable food sources – I understand that some fish will do very well using black soldier fly larvae, worms and other insects. As I live in a warm climate I’m anticipating that my black soldier fly larvae set up (just for home use) will become productive for most of the year. I’m also tempted to try to set up some sort of mosquito larvae breeding ground. Of course, my neighbours would hate me if I let these larvae grow into mosquitoes, but the idea would be to feed them to the fish in an effective way (silver perch – an Australian spp). What I had in mind is small open topped water proof containers with big taps on the bottom, which would drain both water and larvae into the fish tank.

    Your fish guts etc could go towards feeding your composting insects/other, which could then become food for more omnivorous or carnivorous fish. I don’t really understand what various detritivores need in their diet, but perhaps the compost would have some function for their food sources? If you can get 3 or more uses of your compost – that would be great. ie. heat, food for fish, food for detritivores – food for plants:) I doubt any diseases would survive so many links in the food chain.

    Thanks for the article – great stuff!

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