Pheonix Reserve 5-20lb

Raises calcium hardness level safely in pool water to maintain optimal balance. Keep calcium levels at 200 ppm for vinyl and fiberglass pools, and 300 ppm for concrete and plaster pools. One pound increases calcium hardness by 80 ppm in 10,000 gallons of water. Broadcast across the deepest part of the pool while the water circulates. Ideal for pool maintenance. Manufactured in Connecticut, USA