Aquaponics?
Aquaponics is based on the symbolic relationships found in nature and can be loosely described as the combination of aquaculture and hydroponics. Fish effluent from traditional aquaculture systems is used to fertilize plants in a hydroponic system.
When the two practices are combined they work in a symbiotic relationship to create a natural growing system. The benefits of keeping fish in an aquaponic system include maximum efficiency of water. University trials showed that growing plants in an aquaponic system used 90% less water than soil grown crops, as the only water lost is through evaporation and transpiration. In traditional aquaculture water is discharged regularly often 10-20% of the total water every day, this water is often pumped into open streams where it pollutes and destroys waterways.
Instead of discharging water, aquaponics recycles the water in a reticulating system. Water is pumped from the fish tank through grow beds where the water is cleaned by the plants and media before being returned to the fish tank providing the fish with freshly oxygenated clean water. Hydroponic gardening often relies on the addition of costly chemical nutrients using valuable time, energy and money.
By combining the processes we can easily grow vegetables, herbs and fruits simply by feeding the fish. Best of all there is no need to use chemical fertilizers or pesticides.
In an aquaponic system the nutrients are supplied by the fish. They produce ammonia as they breathe and when they excrete waste, this ammonia is converted by beneficial bacteria into nutrients available to the plants. The solids are broken down and filtered in the media beds, effectively cleaning the water before returning it to the fish tank. The good bacteria occur naturally in soil, air and water. They colonise the media and a healthy population is an essential ingredient of any aquaponic system. We can describe this simple process as the "nitrogen cycle" a term that many aquarists would be familiar with. By working with nature we encourage natural processes that can be monitored and recorded for lessons in schools about integrated science, biology, horticulture, health, society and the environment.
There are many different methods that can be adapted to an aquaponic system including flood and drain, floating rafts on deep water channels or using a nutrient film technique, a style that is very popular in hydroponic operations.
Aquaponics is not a new concept, but a century's old technique that has been practiced by elite societies around the world for thousands of years including the Chinese, Aztecs, Egyptians and Babylonians (Gardens of Babylon).
