BioGuard Oxysheen (non-chlorine shock) - 1 Lb BioGuard Oxysheen is a non-chlorine pool shock Destroys contaminants such as perspiration, sun tan oils and other impurities Oxysheen dissolves rapidly and completely. Swimming can resume in just 15 minutes after application Restore sparkle and clarity to your swimming pool water 1lb per 10,000 gallons of water per week