Since aquaponics systems are constantly cycling water, these systems on average use only 10% of the water that would be used growing the same crops through traditional soil means. A well run aquaponics system will constantly cycle its own water - there is no need to change the water, and none is dumped out as waste. The fish and plants team up in a symbiotic relationship - the fish and their waste feed the plants, and the plants clean the water - and it operates in many ways as nature intended. In fact, the only water required in an aquaponics system is enough to replace what is taken away when plants or fish are harvested, or natural losses due to evapotranspiration.
The amount of water required by different crops varies quite dramatically, and so does the savings realized in aquaponics systems. In one Australian study, it was calculated that it required about 10,000 gallons of water to produce $100 AUD worth of vegetables grown in soil. By contrast, the same value of vegetables (and fish) can be grown in an aquaponics system consuming only about 130 gallons of water. Since around 70% of water used in the U.S. today is for agricultural irrigation, this method of farming could lead to serious world-wide savings.
