Imagine having a self sustaining food source in your backyard (or community) where vegetables and protein can be grown in a fairly small space without the use of sythetic fertilizers,chemicals, or even soil!
This is what aquaponics, a system using fish and ciruclating water propose:
In this closed system fish waste accumulates in water which becomes high in nutrients and this water is then fed to plants growing hydroponically.
Plants take up all the nutrients from the water which is returned to the aquatic animal environment and the cycle continues. Aquaponic systems do not discharge or exchange water, the systems rely on the relationship between the aquatic animals and the plants to maintain the environment. Water is only added to replace water loss from absorption by the plants, evaporation into the air, or the removal of biomass from the system.
Aquaponic systems vary in size from small indoor units to large commercial units. They can use fresh or salt water depending on the type of aquatic animal and also can support different types of vegetation.