In The Swim Pool Shock 68% Cal-Hypo Granular Sanitizer for Crystal Clear Water Defends Against Bacteria, Algae, and Microorganisms- 24 X 1 Pound 25266 2X12X1

Powerful chlorine shock treatment that is great for regular maintenance. Quickly eliminates algae, bacteria, and other harmful contaminants from your pool water. Main active ingredient is 68% Calcium Hypochlorite (Cal-Hypo) for quick sanitizing. Dosage: 1 Pound per 10,000 gallons Cal-Chlor granules can be used in swimming pools, spas and hot tubs. Must pre-dissolve/dilute to prevent bleaching of the liner.