CLOROX Pool&Spa XtraBlue 3 Chlorinating Tablets, Kills Bacteria & Stops Algae, 12 LBClorox Pool&Spa XtraBlue Chlorinating Tablets go the extra mile to help maintain healthy pool water. These multi-functional tablets work hard to keep your water clear from both bacteria and unsightly algae. Each tablet dissolves slowly and contains stabilizer for a long lasting clean. The XtraBlue Formula protects your surfaces from scale and corrosion, and includes conditioners that make your water feel silky smooth.Maintaining 1-4 ppm* of Free Chlorine is critical to keeping water clean and suitable for swimming. Use weekly in skimmers, feeders or floaters.Always apply chemicals per label directions. Circulating pool water when applying chemicals helps disperse chemicals throughout the pool for maximum coverage.