HTH 1 Qt. Pool Care Algae Guard Ultra

HTH Ultimate Algae Guard is the strongest algaecide formula available from the brand pool owners have trusted for over 25-years. Ultimate Algae Guard both kills and prevents even the most stubborn green, black and mustard algae. This non-foaming algae guard treats pool water for up to 90-days after applying to your pool �and you can swim just 15-minutes after use.