Intex Electric Pool Heater can help maximize the achievable temperature depending on your pool size, the air temperature and how well the pool is insulated by the use of ground and solar covers. Typically, for a well-insulated 10ft inflatable pool of 3500litres, you can anticipate a 5-6degC rise in temperature above ambient after a 12hour period. Don't forget that the pool will cool at night when the air temperature drops. The heater will be less effective with larger pools which will take longer to heat. The achievable top temperature may also be slightly lower. It can be use for pools up to 15 feet capacity.