A soft, flexible, solar pool heater for floating on water generally comprises independently inflatable outer ring and central portion. When chamber and cavity are inflated, the cavity is with the top and bottom planes of the ring. The ring can be inflated with water for holding the heater in a pool in winds. Holes through the central portion permit egress of air from under the central portion when the heater is placed on water. Valves for chamber and cavity are located near one edge such that the heater may be deflated by rolling from an edge opposite the valves. Magnets on the ring condition water and attach to similar floating heaters to form rafts.