Abstract: A method and apparatus for providing aerated water to a tank used for the rearing of aquatic animals. Positioning of the intake posts and exit drains to establish one or more vollutes of water which substantially fill the tank provides a self-cleaning tank with reduced areas of inhabitability. The method and apparatus permits tanks to be lengthened without a need to add turbulence to the water. An improved method and apparatus for oxygenating water while maintaining nitrogen concentrations within acceptable limits is disclosed as well as a system for energy efficiently maintaining the temperature of the water in the tank.