Abstract: A wash water system for retrofitting a pre-wash tank or sink includes a plurality of spray nozzles which extend along an inner surface of a back wall of a pre-wash sink wherein the spray nozzles are in flow communication with a discharge side of a water circulating pump. A return conduit is provided wherein the return conduit extends vertically downward along the inner back wall of the sink a preselected distance and is in flow communication with a suction or intake side of said pump. The sink is provided with a bottom wall with at least one opening therein and a heater is provided with a conduit extending from the heater to and in flow communication with the opening in the bottom wall of the sink. A vertically extending first filter device is placed along the back wall of the sink over the openings into the return conduits to the suction side of the pump and a second filter device is placed over the opening in the bottom wall of the sink.