Up to 70% of a pool’s heat is lost through evaporation, and between 35-60% of pool chemicals can be lost as well. The solution to this problem is a pool cover, which can retain heat and reduce evaporation when the pool is not in use. There are many types of pool covers, and the right one for you will depend on the size and shape of your pool, how often it gets used, how much work you’re willing to do to apply and remove it, and how much you want to spend.
Bubble-wrap-like solar covers are inexpensive, but can be dangerous since children may not realize that they will not support their weight. Even adults can get in trouble if the cover is not completely removed when swimming. Safety pool covers are ones that can easily support one or more adults and are anchored to the deck.
You should consult with a pool expert to help decide the best cover options for your pool. http://www.poolspanews.com/residential-projects/wrap-it-up.aspx