An intake pipe is positionable adjacent to the bottom of a body of water. The intake pipe has at least one perforate section adapted to receive stagnating un-aerated water. A discharge pipe is positionable between a waterline of the body of water and the discharge pipe. The discharge pipe has at least one orifice for injecting aerated water into the body of water. An intermediate pipe section has an input end coupled to the discharge pipe. The intermediate pipe section has an output end coupled to the discharge pipe. A pump moves water from the perforate section of the intake pipe to the orifice of the discharge pipe. A venturi assembly injects air into water flowing to and through and out of the discharge pipe into the body of water.