An aquaponics fish tank is a combination of hydroponics and aquaculture. The wastes from the fish tank are used to fertilize vegetables growing hydroponically. The plants in turn purify the water for the fish.
In a traditional aquaponics system, large fish intended for food are grown in the fish tanks and any of a wide assortment of vegetables are grown in the hydroponic beds. However, small home aquaponics fish tanks can be created that keep small, colorful tropical fish as pets in the tank and grow herbs or salad greens in the hydroponic bed. These tanks are advertised as being self-cleaning fish tanks that also offer edible produce.