Abstract: A combination bathtub and spa includes a tub enclosure that is adapted to contain a quantity of water, a drain having a drain valve that may be opened to drain water from the tub enclosure or closed to retain water therein, a supply system for supplying water to the tub enclosure, and a lid that is adapted to removably cover the tub enclosure. The combination bathtub and spa also includes a pump having an inlet and an outlet, a suction line that provides a path for water from the tub enclosure to the inlet of the pump, a jet nozzle that is located in the sidewall of the tub enclosure, and a jet nozzle supply line that provides a path for water from the outlet of the pump to the jet nozzle. A filter is provided to filter the water that flows into the tub enclosure, as well as a heater for heating the water that flows into the tub enclosure. A control valve is adapted to open to allow water to flow through the filter or to close to stop the flow of water through the filter.