The Poolmaster Pumice Stone removes hard water, rust, mineral and mildew stains from ceramic tile, grout and concrete surfaces and is 100% natural pumice.
Directions for use:
No need to drain pool. Simply wet the stone, then gently rub stained or scaled surfaces until clean. Rinse surface after cleaning. Pumice Stone is chemically neutral.
Pumice Stone Size: 6" Long X 2 3/4" Wide