Quote Originally Posted by FormerBromineUser View Post
Interesting info, ChemGeek! One part seems strange, though. Year after year with my auto-cover, I actually have to open it during the day in the hottest times of summer to cool the pool down. My water temps (when compared to cover on during the day vs off), tell me that cover-off will cool the water more than cover on. (Hope that makes sense). Maybe that's been a fluke.....
Cover off = more evaporation = cooler water.