Many people have visited the store lately with mustard algae on pool walls.Mustard algae will grow easily due to the high water temperatures, low chlorine and lack of water circulation.You should:Keep free chlorine levels between 2 – 3 ppm.Run pool pump between 8 – 10 hrs/day.Shock pool once a week.Use Mustard Out 60 once a week.Call or stop by the store with any questions!