Nava Shock Oxidizer Water treatment that immediately clears pool water and eliminates chlorine odor. Use to help remove buiild-up of organic wastes. Shock Oxidizer comes in 6-One-Pound bags. Safe for weekly use, and water is ready in 15-minutes. Use weekly during the season to eliminate odors and eye irritation associated with a buildup of suntan lotion, perspiration and other nitrogen-bearing wastes.Comes in a box of six 1 pound bags.