Fish and plants, together. That’s aquaponics: a food-growing form of agriculture that combines fish raising(aquaculture) with soil-less plant growth where the majority of nutrients for the plants are produced by the fish. An aquaponics system allows a large culture of fish to be raised inside of a relatively small physical and ecological footprint. A common term in aquaponics is ‘recirculating’; this is a nod to the natural fill and return of ‘dirty’ fish water that is detoxified, absorbed, and reused. The exchange of water between fish tank and filtration system invites non-toxic, beneficial bacteria to colonize inside the system. These beneficial bacteria are actually healthy nutrients that are channeled into a plant-grow space, providing the plants dissolved nutrients that they eat up.
The Nitrogen Cycle
When fish excrete waste, they release nitrogen in the form of ammonia. Beneficial bacteria arrives and converts the ammonia into nitrate, which is more toxic than ammonia, and then eventually into nitrate, the good form of nitrogen that plants prefer. Because of this symbiotic relationship between fish and plants, an aquaponics system depends on minimal water to be discharged from the system. This process is called the Nitrogen Cycle.
Aquaponics vs Hydroponics: Similar but Different
Hydroponics, another form of soil-less growing in water minus the fish, must dispose of those accumulated organic matter and dissolved nutrients. While hydroponics does reduce the amount of water discharged, the accumulation of organic matter and dissolved nutrients requires the system to be flushed in order to prevent nutrient build up. The discharged water from a hydroponics system poses an unhealthy contribution to environmental pollution.
In an aquaponics system, the nutrients are recovered by the plants. So rather than needing the be discharged, the ‘dirty’ water from the fish tank is detoxified, feeds the plants, and returns to the plants: It’s all recirculating.