Severe algae growth such as black algae is resistant to normal chlorine levels and most liquid algaecides. This product is an extremely powerful algaecide and bactericide formulated specifically to kill problem algal growth.
For best results, adjust the pH level of the water to 7.2-7.6.
Before using this product, turn off your pool pump and remove any automatic pool cleaner.
Brush algae growth with a pool brush specifically designed for this purpose. Carefully sprinkle Black Algae Out directly over the algae growth (see chart below). Use care to prevent skin contact. The slow dissolving characteristic of this product allows concentrated chlorine to attack the growth and destroy it. During treatment process, the water should remain undisturbed for several hours before turning on pool pump. DO NOT USE THE POOL FOR AT LEAST 24 HOURS OR UNTIL THE CHLORINE RESIDUAL HAS DROPPED TO 3 ppm OR LESS.
Brush algae spots daily. A second application may be required.
FREQUENT USE OF THIS PRODUCT MAY DAMAGE POOL FINISH; CONSULT YOUR PROFESSIONAL POOL DEALER. DO NOT USE THIS PRODUCT IN VINYL OR PAINTED POOLS AS DISCOLORATION OF THE FINISH MAY OCCUR.