This varies depending on the size of your pool and what type of pump you have. Ideally you want to be able to turn the water over twice per day. This will keep your pool clear. For example, I have a 16×32 pool with a ½ horsepower pump. We run it for 12 hours a day and our water is always clear. Many people with 1 horsepower pumps who run their pumps 24hrs per day are turning the water over too much! There is nothing wrong with that, as long as you don’t mind spending extra money on your hydro bill!