I have a small pond pump pumping the water from the 17 gallon Rubbermaid bin that I use as my fish tank which has five goldfish. The water is pumped up into the first grow bed (another Rubbermaid storage container) which is about 3.5 ft x 2 ft and 6" deep. I filled this first grow bed with Hydroton expanded clay balls which act as my bio filter. It is here where the microorganisms convert the ammonia from the fish waste into the nitrates and nitrites that feed the plants.
You can grow directly in the Hydroton but I have recently been experimenting with growing in containers filled with vermicompost from my worm bin which are then placed in the grow bed. This seems to help with some of my fruiting plants such as strawberries and peppers. I also have broccoli, beans, and chives in this grow bed. The water is kept at a constant height using a standing pipe which then flows into the four 3 inch PVC pipes. This is the NFT (nutrient film technique) part of this system where the water flows over the roots of the plants as it trickles down the pipe. The plants take the nutrients they need and thus clean the water for the fish.
The upper PVC pipes are 5 ft in length which are connected to the lower pipes which are 10 ft long. The water flows from the top down to the longer pipes which then empties back into the fish tank. I used a 2 3/4 inch hole saw to cut holes every 6 inches in the PVC pipes. I use the red cups which I have poked holes in using a soldering iron although net pots would be ideal. Leafy greens do very well in the NFT pipes. I currently have about 126 leafy greens growing including Swiss Chard, Romaine and Simpson lettuce.
All this in a 10 ft x 2.5 ft space in my basement. I use eight T12 shop lights from Walmart with plant and aquarium bulbs which are set on an automatic timer that keep the lights on for 14 hrs a day. The total cost of this system was about $350 and costs less than $12 a month in electricity to run the pumps and lights. This system provides me with several fresh organic salads a week, endless fun, and my two year old twin daughters love to help feed the fish and pick the lettuce which is of course, priceless.
Steve Wolfort may be reached by commenting to this blog - questions are welcomed or by Member email.