E-Z Patch 4 F.S.® Underwater (Fast Set) White Pool Tile Set & Grout Repair is an underwater fast set mixture used for setting or grouting tiles underwater. This product contains special modified materials with pozzolans (siliceous volcanic ash) and polymers. Liquid acrylic bonder is not needed on this kit. Swimming allowed the next day after application. Available in 1 lb., 3 lb., 10 lb. & 50 lb. sizes.