What Is Aquaponics
Aquaponics is an agricultural system combining aquaculture and hydroponics. Aquaculture being the act of farming fish, crustaceans, molluscs and aquatic plants, and hydroponics being the act of growing plants in a system without using soil. Aquaponics is a sustainable, natural way of producing not only fresh vegetables and fruits, but also fish. There are no chemicals involved and the plants survive solely on the nutrients from the fish water. Aquaponics involves a fish tank and a garden bed sitting near each other with two pipes and a small pump. One of these pipes will pump the old fish water from the fish tank into the garden bed, this is where the plants take out the nutrients out of the water, essentially cleaning the water. The fresh water then goes back through the other pipe back into the fish tank. This system works because the fish will almost always have fresh water and the plants get all the nutrients they need from the fish.
The Nitrogen Cycle
The nitrogen cycle is a major part of the aquaponics system and without it, the system would not function. So how does it work? The fish faeces, food waste and any other plant/animal based matter, produces ammonia (NH3) in the water. This ammonia in the water is toxic to the fish and plants. There is bacteria, nitrosomonas sp. and nitrobacter sp, that break down the ammonia in the water and change it into nitrite (NO2-). Nitrite also kills the fish. The bacteria then go and change the nitrite to nitrate (NO3-). Nitrate is also toxic to fish. The plants in the garden, take up this nitrate so the water is clean again.