Shock and sanitize your pool, spa, and hot tub with Spa Depot Dichlor Granular Shock. These easy to use chlorine granules dissolve fast. Control algae, kill bacteria and destroy odor causing organic contaminants in home hot tubs and swim spas. Also an ideal choice for super chlorination, or use with alternative sanitizers. Promotes clean, crystal clear water. Equal to or more effective than other sanitizer brands. EPA Registration No. 46043-11-82043