Robelle 16 lb. Pool Calcium Hardness Increaser

Robelle Calcium Plus is used to raise calcium hardness levels when measures drop below the recommended range of 200-400 ppm. If calcium hardness levels are too low the "soft water" will corrode pool equipment, etch pool plaster and may cause metallic stains. This is a dry granular product that increases the total hardness in pool water to the recommended range. Directions for use: Test for calcium hardness with a reliable test kit. 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 lbs. of product per approximate 5 Gal. bucket of water. Slowly pour this solution around the perimeter of the swimming pool while the circulating system is operating. In a 10,000 Gal. pool, do not add more than 10 lbs. of this product per 2 hour period. For 5,000 Gal. 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.