Wadoy Pool Stain Eraser 3 Pack for Plaster Concrete Spa Pool Pumice Stone Removing Rust Spot

1.Q:Can this be used on the tiles around the top of pool? A:we can use it to remove calcium buildup with this tool, and it didn’t scratch the tiles; it takes time to use this, but the results were worth it; 2.Q:Is this really pumice stone? A: It is much more dense than the typical pumice we've used. However, it could do a good job removing scale from our pool tiles without scratching them. Note: Do not use this pumice stone on fibre glass or vinyl liner pool surfaces.