PoolStone Pool & Spa Cleaning Block not only works better than your current pool tile and grout cleaner, it’s also easier to use. The block conforms to the shape of your tile and grout, providing better coverage than a regular grout cleaner. PoolStone Blocks may be used on Gunite, plaster, tile, grout and concrete of in-ground pools/spas. PoolStone is an excellent tile and grout cleaner. Get the PoolStone block and the surface to be cleaned very wet. Frequently rinse out block either in the pool or with a hose and keep wet for best results. Don’t press hard - let the PoolStone do the work. For tile, use PoolStone flat against the surfaces. For grout, begin holding the stone tilted slightly on edge. This will help it conform more quickly to the shape of your pool’s tile and grouting. Not reccomended for use on overglazed tile decorations, vinyl, acrylic fiberglass, wood or polished metal surfaces, above ground pools or plastic liners. Poolstone will restore and revive your pool tile.