All-Clear Green Algaecide 32 Oz
Shock your pool and make sure the water chemistry is balanced. pH should be 7.2 to 7.8, and chlorine level should be 1 - 3 ppm. Apply algaecide as directed on the bottle and allow up to 36 hours for the green algaecide to work. Pool should eventually turn to a cloudy milky white and then clear. Run your filter to remove dead algae material and you may want to consider using phosphate remover to inhibit algae growth by removing algae nutrients from the pool.