Pools lose energy. That is a fact. Evaporation is the largest source of energy loss. When the air temperature drops below your pool’s temperature, heat is evaporating away. What can be done? The U.S. Department of Energy says it best: “Currently, the most effective method of controlling evaporation is to cover the pool…” This translates to energy savings of 60 to 80 percent. A ThermGard® Insulated Swimming Pool Cover system by Universal Filtration will save you money.