I agree with watermom!! I have never had any problems with algae but only once and it was from leaving the solar cover on during the hot days in July! I started to notice that there we little like glue balls floating around the pool. I went to the pool store and got yelled at (my friends) for having the solar cover on and this was the cause of my algae. That was a couple of years ago, but I put 2 oz of Omni breakout 60 in everyweek just for a preventative in the hot months.