Coverstar A5003 Molded Housing Assembly 822 Up to 20' - Every pool owner has to contend with some amount of heat loss and evaporation, but an automatic cover can make heat loss and evaporation more manageable. Pool covers can help to keep your pool at a nice, warm temperature, minimize water evaporation, and reduce the need for costly pool maintenance. A Coverstar automatic pool cover helps you save big on heating, electricity, water and pool chemicals, and lets you enjoy a cleaner, safer pool.