Solar Swimming Pool Covers
WarmYour Pool Water with Solar Power
Solar swimming pool covers are essentially giant sheets of bubble wrap that you put on the pool to help heat up the water and keep it warm. The best way I can think to describe it is that a solar pool cover basically traps heat from the sun in the pool (keeps it from evaporating/dissipating). It helps the pool warm up more than normal during the day, and it keeps the pool warmer than it would stay during the night time hours. A solar pool cover can help heat your pool up quicker during the early months of the season, and it can help extend your swimming season into the fall.
To do this, in early Spring, you simply put the solar cover on for the night, and then pull it off in the morning so the sun can warm the water during the day. At night we repeat the process.
The only problem, if you want to call it a problem, is that you usually don't have a roller or anything to easily roll the cover up in the morning. You can buy these rollers, or maybe even make one yourself, but they are expensive. So, since you probably won't have a roller, you simply pull the solar pool cover back and fold it up on the one end of the pool. It doesn't usually look the best and takes up room (just sitting on the cement by the pool), but this really isn't a problem since you probably won't be entertaining a lot during this time, and the benefit of having warmer pool water far outweighs the hassles of the solar swimming pool cover.
If you really want to extend your swimming season, the investment in a solar swimming pool cover is certainly well worth it. I believe that most of these solar pool covers will be less than $100.