Initial Treatment for Prevention of Algae Growth in Clear Pool Water: Use 8 to 12 fluid ounces of this product for every 10,000 gallons of water. Initial Treatment for Pools with Visible Established Algae: Use 16 to 24 fluid ounces of this product for every 10,000 gallons of water. Remove dead algae by vacuuming. Black Algae Control: Apply 16 fluid ounces for every 10,000 gallons of water when algae first appear. Brush spots daily to remove dead algae. Vacuum out settled algae. To Maintain Pools, Free of Visible Algae Growth: Use 4 to 8 fluid ounces of this product per 10,000 gallons of water weekly.