4 lb Bag Nuclo Calcium Hardnes
Basic Calcium Hardness raises the calcium hardness of swimming pool water. The ideal calcium hardness range is 200-500 ppm. Maintaining calcium hardness below 200 ppm may cause corrosion of metal and plaster surfaces.
Test calcium hardness monthly and add this product if calcium hardness is below 200 ppm.
Use convenient dosage chart on product label.
If a large amount of Calcium Hardness is required (more than a 50 ppm addition), add in 1/3 increments, allowing 4-6 hours between additions.