PHOSPHATE REMOVER +PLUS For best results: Treat existing algae with an algaecide and sanitizer first. Application: Apply the product around the perimeter of the pool while the filter is running. Following dosage on the label. Do not backwash or clean during this period. Add one and half ounces of Clearex 500 per 10,000 gallons of water to help keep water clear during treatment. ( Applying smaller amounts of Phosphate Remover Plus over a period of days will help reduce clouding). Apply a maintenance dose weekly or monthly. Test your pool water regularly and keep the water balanced.