Abstract: The tub has a disposable plastic liner configured to the shape of the tub. A pump assembly, having a housing and an electric motor within the housing, drives a drive element. The liner has an opening aligned with the pump assembly, and that opening is sealed around its periphery against the impeller housing of an impeller assembly. The impeller assembly in turn attaches to the pump assembly, preferably in a readily releasable manner such as by the use of magnets. The impeller housing contains an impeller, having a drive shaft which extends through a seal in the rear of the housing and is has a coupling which is engaged by the drive element to rotate the impeller. A cover plate having impeller inlets and outlets attaches to the impeller housing on the tub side of the liner. The entire tub liner and impeller assembly may be removed and disposed of after use.