Abstract: A swimming pool with a convertible hot tub that may be easily installed or removed by a user. A barrier system, having a removable partition formed from a flexible sheet of material, is placed in the pool tank near an area that includes a hot water inlet nozzle. The partition has fasteners formed as peripheral ribs that slide into slotted channels secured to opposite sides of the tank. A water drain is located in the pool area. A water processing system, having a pump and a water heater, is connected between the drain and the inlet nozzle to remove warm water from the pool area, heat the water and supply hot water to the inlet nozzle to increase the temperature of the water in the hot tub. At equilibrium, the partition permits water to flow from the hot tub into the pool area at a rate substantially equal to the rate at which water is supplied to the hot tub via the inlet nozzle.