The desired range for calcium hardness is as follows: Vinyl Pools - 200-300 ppm. Tile and Exposed Aggregate Pools - 200-400 ppm. Marcite, Fiberglass or Painted Pools - 250-400 ppm. If the calcium hardness tests less than the desired range, add this product according to the guide below. Place this product into a plastic bucket already filled with swimming pool water. Do this in a ration of up to 2 pounds of product per approximate 5-gallon bucket of water. Slowly pour this solution around the perimeter of the swimming pool while the circulating system is operating. In a 10,000 gallon pool, do not add more than 10 pounds of this product per 2 hour period.
For 5,000 gallon pool: to increase by 10 ppm add 7.2 oz., to increase by 20 ppm add 14.4 oz., to increase by 30 ppm add 1.35 lbs., to increase by 40 ppm add 1.8 lbs., to increase by 60 ppm add 2.7 lbs., to increase by 80 ppm add 3.6 lbs., to increase by 100 ppm add 4.5 lbs.
For 10,000 gallon pool: to increase by 10 ppm add 14.4 oz., to increase by 20 ppm add 1.8 lbs., to increase by 30 ppm add 2.7 lbs., to increase by 40 ppm add 3.6 lbs., to increase by 60 ppm add 5.4 lbs., to increase by 80 ppm add 7.2 lbs., to increase by 100 ppm add 9 lbs.
For 20,000 gallon pool: to increase by 10 ppm add 1.8 lbs., to increase by 20 ppm add 3.6 lbs., to increase by 30 ppm add 5.4 lbs., to increase by 40 ppm add 7.2 lbs., to increase by 60 ppm add 10.8 lbs., to increase by 80 ppm add 14.4 lbs., to increase by 100 ppm add 18 lbs. 100% Calcium Chloride Compound.