We have an solid color safety cover on the pool. We keep it closed early in the season. During mid summer we tend to leave it open 24/7 because it seems to help with some alkalinity problems we used to have. Of course this summer due to global warming we have had to run the heater everyday except 5 since mid May and keep the cover closed just to keep the pool swimmable. Do the clear solar cover really work that well. I know when we keep the cover closed when the temps are up the pool can get up to 90+ in a day or two with no assistance.