Backyard Aquaponics
A place to discuss aquaponics

Hello all,
This is my first post. Ive been super busy the last three years developing my system and have had great success. I am running a 30'x48' greenhouse, 'growing power' vertical bed style. I am enjoying my dual-root systems (soil pots) that sit in both deep media ibc totes and shallow media runs (see growing power model). I also grow AP classic style in just rock.I grew 1000+ pounds of watercress in shallow media bed, with river rock media last year! The dual root is highly advantages because I can give nutrients directly to the roots (mostly P and N) when i feel its needed without having to manipulate the water mass. I heat with a central wood boiler that I send hot water to my tanks' in-floor heating (insulated son the ground and then pex-al-pex separated by the plastic floor to my 'trench' tanks.) Ok i think thats enough info there...
My next big project is to grow ALGAE at a rate that i can use it to be the sole feed of my fish food, and see good growth rates of my fish (tilapia). I am currently NOT feeding my fish at all. They survive from the algae and inverts that i wash down into the tank from it growing in my shallow media beds (mostly filamentus). This is enough for the tilapia thrive and be healthy but not growth much. For this reason, i believe if can get enough algae into their gill rakes they will have enough food to have good growth rates. I am looking at having an IBC that has my culture (spirulina, so i can eat it too), in which i will give nutrients and co2, and then pump through thin-walled pvc tubing for sunlight, and return back to the IBC culture tank. The tubing will run the length of my greenhouse and attached on the structure. This is all done in a separate and independent loop than the AP system.
From there I will simply inoculate the tanks and allow the fish enough time to collect the algae in their gill rakes before i turn the pumps back on for the water to circulate the AP system, or better yet, i will have a filtration method to condense the algae so that the tilapia can feed on it at greater rate and efficiency. 50 micron screen is suitable for spirulina.
If this works, I will have an endless source of the best fish food (and human superfood) on the planet!
Questions/comments for the public:
has anyone done this?
I know my obstacles to success are;
-growing enough algae to be effective
-making sure the algae doesn't overrun my system once in the water column (taking all the nutrient and oxygen),
-filtering the algae from the grow system at an effective rate... their are some sweet filters for bio-fuel industries, but a 50 micron screen works as well.
-Does anyone know of charts that can provide feed/growth rates with algae rich water for tilapia?
Well I hope this gets the conversation started. Growing Algae (spirulina) has infinite uses in horticulture soil science and human health potential. It can truly make our systems a bit more 'sustainable' if harnessed correctly. The power of the sun is all that is needed once its gets going...tho co2 and extra nutes may bump it up a bit!
Thanks for your time! happy gardening!
Justin at Sacred Valley Farm in Durango, CO

Hi Justin, welcome to the forum .



Can't recall ever seeing a chart with this information but I'm not really focused on Tilapia .

Cheers