Aquaponics water usage

How does the water usage compare to other means of raising fish and plants? The amount of water used is significantly smaller. Believe it or not, aquaponics water usage is only 5% (or even less) than what used in conventional techniques. Welcome to this aquaponics resources page on water usage.

In aquaculture, fish waste increases levels of ammonia, nitrite and nitrate in the water. Even with expensive filtration systems, the water has to be replaced regularly. This waste water will be dumped into the environment and can contain unwanted levels of these chemicals.

In hydroponics, nutrient chemicals are added to the water manually. Eventually, the levels of the nutrients will become too out of balance and the water will be replaced with fresh water. The water in the system will then be disposed of in the environment.

Aquaponics is a closed-loop system

The aquaponics water usage is incredibly low, no water is wasted as the system is designed in such a way that it is always in balance. Nutrient rich waste water from the fish tank is transformed by good bacteria into nutrients that the plants thrive on. The water flows to the plant beds (where good bacteria also convert fish waste into plant nutrients) and the plants use these nutrients to grow. The water is thus filtered. The filtered, cleaned water is then returned to the fish tank. This cycle can be continued forever, without wasting any water at all. Aquaponics is thus truly a closed-loop system. Both fish and plants are produced in a single system with an absolute minimum of water usage.

Water usage comparison - Fish

When raising fish in an aquaponics system, little or no water is wasted as the plant beds continually filter out the waste as their nutrients and the water can be reused for the fish tank. See the table below just how big this difference can be compared to other methods of raising fish.
Open water net pensNo additional water is used, but precious open water space is used for raising fish and care has to be taken that the environment can sustainably handle the fish waste produced by open-water net pen operations.
Non recirculating raceways and tanks5.000 - 10.000 gallons per pound of production.
Non recirculating ponds500-1.000 gallons per pound of production
Recirculating systems5-10 gallons per pound of production
Integrated aquaponicsNo waste, water is used and cleaned by the plants and returned to the fish tank.

Water usage comparison - Plants

The difference in water usage for watering the plants in an aquaponics system is absolutely stunning. With a large margin of safety, water usage is less than 5% compared to traditional forms of gardening. Imagine the consequences of this in dry regions! As a benefit, the nutrients are kept in the system. In conventional gardening, irrigation will wash the soluble nutrients down, and out of reach of your crop. In aquaponics, this is not possible.