My daughter grows organic veggies hydroponically. She has 15 gallon reservoirs filled with pea gravel and a 100 gallon reservoirs filled with fish. The gravel filled reservoirs are higher than the fish one. Using a bilge pump, she pumps fish water up to the veggies and gravity feeds it back into the tank of fish. The theory is the fish water feeds the plants and the gravel purifies the fish water. She chose koi for her fish but a lot of people raise tilapia this way.
Right now she is growing leafy greens, peas and a lot of herbs. This whole setup is in a temperate greenhouse (the temps fall to near freezing before the heat comes on). She plans to add summer veggies with too long growing seasons this spring.
Daisy
