If you buy a winter cover designed for above ground pools, it must come with a cable and winch to adjust the cover. A retailer that sells pool supplies and equipment can give you a quote based on the unique dimensions of your pool. Putting on the cover is the last step in preparing for winter, according to Gail Rose of Colley's Pools and Spas. A standard winter cover is similar to a tarpaulin and helps retain heat, keep the pool free of debris such as leaves and dirt, block sunlight, and inhibit algae growth. If the pool water freezes during the winter and the ice expands, it can cause the pool to separate and flood your patio. Pool covers also provide important protection for children and pets.
For pools that rely on the sun for warmth, covering it at night can make it warm enough to swim the next day. Standard winter covers are cheaper than safety covers but require more labor for installation. If the cartridge accumulates a high level of chlorine or other harsh chemicals due to lack of circulation, the cover may deteriorate.