System Components

• 4 fish rearing tanks fiberglass 8' diameter x 4' high, 1250 gallons.
• 2 cone bottomed settling tanks for removal of solid waste Kalwall7 4' diameter x 4' high cylindrical tank with a 3' high x 60" cone bottom, 500 gal. A center baffle crosses the tank to prevent solid waste from flowing directly through to the outlet. We constructed our own but similar tanks can be purchased from fiberglass manufacturers.
• 4 rectangular tanks fiberglass 2' x 2' x 6', 180 gal. These hold 100'l x 6'w bird netting that traps fine suspended solids.

• 3 round tanks fiberglass 2' diameter x 32" high, 60 gal. Header tank controls flow of water into hydroponic tank. Also holds additional bird netting.
• 6 hydroponic beds arranged in pairs, poured concrete or concrete block option 18" high x 4'2" wide x 98' long, inside dimensions. Poured concrete walls are 6" thick reinforced with lengths of rebar on both the horizontal and vertical plane. Block walls are 2 blocks high with rebar stakes in holes, durawall7 and mortar between layers of block, block cores are filled with concrete. The choice of poured concrete or block is dependent on the number of systems being constructed. If multiple systems are to be built then the materials needed for building forms (plywood) can be absorbed by the greater number of tanks. If only one system is proposed then block walls are a cheap and reliable alternative.
• 6 hydroponic tank liners Low Density Polyethylene (LDPE) 104' x 9' x 20mil We have tested 5 different liner types and find this to be the best. Vinyl liners deteriorate in the sun and shrink when dried. Thicker polyethylene (60 mil) or High Density (HDPE) is more brittle and difficult to shape into the tank corners. A Permalon7 liner had a short life. Measure your concrete or block tank for exact dimensions before ordering liner material. The material should lie flat on the tank bottom go up each side, over the top of the concrete wall and down the outside edge about 8". A 1" x 2" pine furring strip can be nailed or tapcon-screwed to the liner and the tank to hold the liner in place. (Note: Our system is a modified and expanded version of two smaller systems. A better system would have 2 hydroponic beds (one pair). Each tank would be 12'3" wide x 99' long. This will provide the same growing area with 8 fewer walls to build. The liner for the tank would be appropriately sized, approximately 20' wide saving 7' x 105' in material. In each bed is the equivalent of three tanks. Only one header tank is needed to supply water to the hydroponic tank.)
• 1 reservoir tank fiberglass 4' diameter x 34" high, 240 gal. Holds water returning from hydroponic tanks. Water is continuously pumped from this tank into the fish rearing tanks. A float valve regulates depth and automatically allows water additions from supply source.
• 1 circulation pump 70-100 gal/min