Aquaponics is a relatively new agricultural practice that started in the 1970s that integrates aquaculture with hydroponics. It’s has the potential to greatly increase local food production, and improve the efficiency of existing aquaculture and hydroponic practices.
Aquaponics is a positive cycle where the waste of one system is used to sustain the other. The excretions of the fish have high levels of ammonia. The ammonia saturated water is then fed to a separate vessel filled with lava rock. The porous lava rock is home to nitrosomonas bacteria that converts the ammonia to nitrites. The nitrite is then transformed by nitrobacter bacteria into nitrates which are a highly effective plant fertilizer.
The water, now with high concentrations of nitrates feeds the hydroponics operation. The water is pumped up to a higher elevation where gravity returns it to the fish tank via all of the plants. During the trip, the plants remove the nutrients from the water and the travel oxygenates it. The clean water returns to the fish tank where the cycle begins anew. If the water was not cleaned, the ammonia levels would become too toxic and kill the fish.
Excess plant waste can be used to as fish feed, however, in most systems additional fish feed still needs to be added. The most popular fish used in Aquaponic systems is tilapia. It’s a hardy, disease resistant and fast-growing fish suitable for fast-growing fish suitable for human consumption.
Aquaponic operations are quite popular in the United States, Europe and Australia. Adoption of aquaponics are just starting in Canada. The largest Aquaponics operation in the world is an outdoor system located at the University of the Virgin Islands.