Hard water stains leave dark spots and discolored areas on granite floors and countertops. They mar an expensive marble countertop or floor. How do you remove hard water stains from stone floors and counters? What do you do if you have hard water stains in a ring around the faucet of your granite sink or marble shower tiles?
White mineral deposits from hard water stains occur when you have not sealed the countertops (or the seal has worn off) and you don’t get in the habit of cleaning water spills immediately. If your countertop seal has been compromised, don’t try to remove the hard water stain but call a professional so you don’t make matters worse. If you don’t know, sprinkle a little water on the counter. If the water seeps into the counter and didn’t before, call a pro. If the water beads on the surface, then the seal is still good.
Before you start prepping to remove hard water stains, scrub the surface in case it is spilled dish soap or something similarly removed by a little elbow grease. Don’t use abrasive scrubbers on the granite or marble counter top, though, or you’ll damage the seal or the countertop or both. Use the back of a sponge, soft bristle brush or nylon pad to scrub it instead. If you don’t know if the stain is from hard water or food residue or really don’t want to scrub it, put granite cleaner on the stain and let it set in for 20 to 30 minutes. Never, ever use ammonia based cleaners because it will damage marble. Bleach and hydrogen peroxide are nearly as dangerous to your marble and granite stone surfaces. Instead, use stone safe cleaners or make your own with baking soda or talc. Very diluted ammonia and hydrogen peroxide (but not both) can be added to talc to improve its cleaning ability. Rinse the cleaning mixture completely off the stone surface to avoid discoloring it.
Then scrub it but for not more than five minutes so you don’t damage the seal or stone. Rinse with water that you immediately dry up. If there is a possibility the white residue is soap residue, use stone safe soap film remover and then move to the step below.
If you are ready to remove the hard water stain and scrubbing isn’t enough, get a plastic scraper. This is the default solution if you’re finally tackling hard water stains around a leaking faucet. Use that to try to lift up the stain. If that doesn’t work, you can resort to the classic solution – a clean, sharp razor blade. With a steady hand, gently scrape the mineral residue away. Don’t scrub hard because you’ll damage the seal or the granite itself. This is why we don’t recommend steel wool – too many people will automatically apply pressure and damage the material. Instead, make several passes. Always use the softest tool and repeated effort before you take the risk of damaging the stone.
After the hard water stains have been scraped away, use a soft cloth and stone countertop cleaner, or, lacking that, dish soap with a little water to lather up before you then thoroughly rinse away and dry. Vinegar is often touted as a way to remove hard water deposits, but the acid in it risks pitting and damaging the sealant.