·The XtraBlue+ 3" Chlorinating Tablets are designed to kill bacteria, clean water, and prevent algae growth in swimming pools. These 3-inch tablets provide long-lasting sunlight protection and prevent corrosion, scale, and stains. They also condition the water to make it feel silky smooth. For effective use, apply the tablets weekly in skimmers, feeders, or floaters, following the label directions. The Clorox Pool app can provide personalized recommendations for your pool's needs based on weekly water tests. These tablets are a  convenient and reliable solution for maintaining a clean and safe swimming pool .