The water temperature in swimming pools can be regulated using active solar heating systems, extending the swimming pool season. From mid-spring to mid-fall there is a great deal of solar energy that can be collected. For outdoor pools, a properly sized solar water heater can replace a conventional heater ?saving a tremendous amount on fuel bills and extending the swimming season. Indoor pools that are used year round generally will have a conventional heater as backup. Using a pool blanket is highly recommended, regardless of how the pool is heated. Heating a pool without a blanket is like heating a house without a roof on it; heat loss is instantaneous. Further, pool blankets reduce the loss of expensive pool chemicals through evaporation.
In a typical solar pool heating system, solar collectors are mounted on a nearby roof and connected to the existing filter pump. Most solar pool heaters use cost effective unglazed collectors. When the pool needs heating, water is diverted to the collectors where it is warmed and returned to the pool. Generally speaking, a pool will need a collector area equal to 50 to 75 per cent of the pool surface area.

Pool water is pumped to the solar collectors, entering at the bottom and rising to the top through the individual tubes of the collector. As the water flows through the individual tubes of the collector it is heated by the sun's radiant energy. The water then returns to the pool. This cycle is repeated until the pool is sufficiently warmed by the sun. This process is fully automated using a temperature differential controller and thermostats.
KM SOLAR recommend that a separate pump is used for the solar pool heating system. In this way, there is no conflict between the activities of heating and filtering and less strain is placed on the pump to achieve both aims.