If you live in a place where there is a high level of lime, magnesium, and calcium in the water supply, then you have what is known as hard water. And chances are, somewhere in your home, whether it’s around a leaky faucet or in the bathtub where the water leaks, you have hard water stains.

How to remove these stains depends on where they are located. Phosphoric acid is the base of most cleaners, and even the average household bathroom cleaner will have around 6% of this content. However, that may not be enough for stubborn stains or buildup.

When you prefer not to use chemicals, you can first try soaking the area with white vinegar and letting it sit for half an hour. That should penetrate the residue enough that it can be scrubbed or scraped off later. If not, you may need a cream cleaner if you have stains on acrylic surfaces, or a vitreous enamel cleaner for things like the toilet, sink, or bathtub. If the buildup is on the metal surface of the faucet or mounts, you can try scraping it off with a razor blade after it has softened, but be careful not to cut yourself and scratch the fittings.

Bleach can remove some stains, like toilet bowl stains, but don’t leave it in for too long, as it can affect the shine of your polish. Truly stubborn stains may need a commercial cleaner. However, if you’ve been trying other solutions first, be sure to rinse thoroughly, so there aren’t potentially harmful interactions between the chemicals when you apply another cleaner.