In the UK, due to our ever changing weather pools need to be covered, Blue Cube Direct have a great selection of covers.
In the summer a solar pool cover transfers heat from the sun to the water and prevents heat loss due to evaporation as well as insulating the surface. In the winter a debris cover keeps leaves etc from blowing into the pool. The lighter weight solar covers can be taken off by hand off a small pool but removal is made easier with a reel. Reels can be manually or electrically operated.
Pool safety is a concern for families with small children so safety covers are increasingly in demand. These also can be manually or electrically operated. A pool safety cover is used summer and winter instead of a solar and winter cover. Indoor pools will benefit from heat retention covers to reduce humidity and heat loss.