Recirculating aquaculture systems represent a new way to farm fish. Instead of the traditional method of growing fish outdoors, this system rears fish at high densities, in indoor tanks with a controlled environment. Recirculating systems filter and clean the water for recycling through fish culture tanks. Water is typically recirculated when there is a specific need to minimize water replacement, to maintain water quality conditions which differ from the supply water, or to compensate for an insufficient water supply.