Abstract: A combination water softener cabinet and brine tank is adapted to have a water softening resin tank housed therein in an area adjacent the rear wall, while an area within a forward portion of the cabinet and alongside the resin tank serves as a brine containing area. Reinforcing indentations in the molded plastic side walls for the cabinet cooperate with the rear wall of the cabinet and a socket structure on the bottom of the cabinet for retaining the resin tank against lateral displacement within the cabinet. A combination resin tank locating, retaining and hold-down device comprising a plate provides with upper structure of the cabinet an isolation chamber for protectively housing the softener cycle controlling mechanism mounted on the resin tank against brine fume damage and against contamination from salt during charging through an opening in the upper front portion of the tank.