The combination of hydroponics and aquaculture (the farming of fish) is known as aquaponics.
Plants and fish live together in ecosystems and have done so since time began. The plants provide food for the fish as well as filter the water, while the fish provide food for the plants.
In fact, the Aztec farmers as well as Chinese and Thai farmers, used fish in their gardens. In modern society, some commercial hydroponics growers actually use aquaponics to grow their crops.
The Aqua Vita farms in Sherrill, for example, use aquaponics to grow basil, salad greens, and lettuce commercially. They have a huge fish tank from which the water is filtered to remove solids, after which is moved to a reservoir on which plants float.
The plants filter the water, using all of the nutrients that are contained within it. The water, which has been cleaned, is then passed back to the fish tank.
I have been thinking of using this sort of system in an indoor hydroponics setup. It would be really cool to have a fish tank, on top of which a small crop of lettuce is growing. It would also be mega cool if there wasn’t the need to clean the fish tank any longer since the plants were doing such a good job of it.
It remains to be trialled and tested.
