Our Aquaponics Efforts

We've been growing tilapia for about ten years and have had aquaponic grow beds for about eight years now.

Chocolate Peppermint in one of our grow beds.

At this writing we have three IBC totes serving as water tanks--two for fish and one as the sump tank, holding about 500 gallons of water and about 20 tilapia. The water and fish support two 4 x 4 x 1.5 foot grow beds filled with hydroton (expanded clay pellets) as the growing medium.

The water is continually circulated from the fish tanks through the growing beds and back into tanks. The fish make waste that is broken down by naturally occurring bacteria into food the plants absorb and use--cleaning the water for the fish. It is almost a closed system--the fish eat some of the plants growing in the system, but we do have to supplement their feed.

We test the water weekly (or more often if needed) to insure that the amonia-nitrite-nitrates process (bacteria breaking down the ammonia into plant-usable components) is working, and that the pH level is tolerable for plants, friendly bacteria, and fish. We add no fertilizer (the fish do that), though we do have to add chelated iron once in a while (the need indicated by chlorosis in the plants) and water as transpiration and evaporation take their tolls, but nothing else on a regular basis.

Here is a look at our fish:

The green stuff to the left in the video is duckweed grown in a floating container on the surface of the water--so that the duckweed can grow without the fish eating it. We harvest a little bit of this at a time as a daily treat for the fish. The green reflected in the water is the chocolate mint (pictured above) in the grow bed supported by these fish.

 We are planning to add a deep water culture (DWC) tank (using the rafts to grow greens directly in the water), but probably will have to move our whole system (or build an additional one) to accommodate the new tank.


Here is a video showing a large DWC operation.



(h/t to Gene Alley for the share on Facebook.) With solar power to run the pumps and grow lights, this could be a very sustainable system of food production. One major advantage/benefit to this system is that it can be done indoors (in a large warehouse) in the city, reducing transportation costs, increasing freshness and nutrition delivered to the consumer, and no chemical fertilizers, pesticides, or herbicides need be used. Input to the system could be simply water, occasional iron chelate, and food for the fish.

Australian aquaponic growers we follow have found that perch (their aquaponic fish of choice) and tilapia can be fed as we feed our chickens--greens, insects, grains, table scraps, etc. The offal from the harvested tilapia could be turned into fish emulsion fertilizer to grow crops for fish food and other crops for human consumption in soil containers and garden plots. Aquaponics could be an important cycle/system in a sustainable and cost effective food mass production system. It certainly works for us. We intend to expand our efforts and more fully integrate the system into our mini-farm production.

We encourage you to look into this ancient and yet modern and potentially self-sufficient food production technique. If we can do it, so can you!

We have read, applied, and recommend:
 Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together by Sylvia Bernstein.