Aquaponics is a sustainable agricultural system that combines aquaculture (raising fish) and hydroponics (growing plants without soil). In aquaponics, the waste produced by farmed fish provides nutrients for plants grown hydroponically, and the plants help filter the water, which is then recirculated to the fish tanks. Aquaponics systems can range in size from small indoor units to large commercial operations. The system mimics the nitrogen cycle to transform harmful ammonia from fish waste into nitrates that plants can use as nutrients while purifying the water.