text: I started to notice black algae spots in my salt water inground pool. With the pump off I added about 2 lbs of salt then used a wire brush to remove the algae spots. The salt helped loosen the algae. Ran a quick clean cycle then cleaned the filter media. Brushed the pool again to remove any missed algae spots. Checked chemical and balanced. Added product according to directions. Ran pump for 10 hours. Removed filter media and cleaned again. Pool water is now crystal clear and no more spots. I hope this helps.