Abstract: An aquaculture system for growing aquatic animals such as fish and crustaceans is shown and described. A rigid-walled floating tank is positioned in a body of water, a volume of water being provided to the tank via a floating pump assembly that is positioned in the body of water external to the tank. An inlet of the pump assembly is movable and may be positioned in a desired location and depth of the body of water, such that clean water that is free of surface contaminants and that is at a selected temperature is provided to the tank. The introduction of new water to the tank displaces and discharges a volume of water from the tank, thereby renewing the oxygen source in the tank and removing dissolved waste products such as ammonia. Additional oxygen may be injected into the water at different locations via oxygen diffusers.