Abstract: A spa having a filter assembly mounted in a sidewall and accessible through the coping at the top periphery of the spa. The filter assembly has a plurality of filter elements and a chemical dispensing mechanism easily accessible and replaceable through the coping. The filter assembly is downstream of the pump and heater to prevent cavitation erosion of the pump impeller. A pressure valve allows water to by-pass the filter assembly when clogged or operated at high pump rates. The top of the filter assembly is concealed in a well defined in the coping and closed by a cover having a profile matching that of the coping.