If you have hard water in your home, then you have probably finished a session of window cleaning feeling frustrated and defeated. Hard water stains leave white streaks behind no matter how much you clean your windows. It’s annoying when you clean your windows regularly but can’t remove the stains left behind by the calcium in hard water. Here's what exactly causes these stains and how you can finally get rid of them. 

What Causes Hard Water Stains?

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In the majority of U.S. homes, the water contains calcium carbonate, which is dissolved into the ground water. When this water gets on a surface and then evaporates, it leaves behind the calcium, which appears as white streaks or spots.

You probably notice it most on glass shower doors or at the bottom of your windows, especially where any sprinklers may spray water. As the water evaporates, the white stains form and create a film on the glass that doesn’t come off with typical glass cleaners. 

How Can You Prevent Hard Water Stains?

The longer the calcium stains remain on the glass, the harder they are to remove. Calcium stains can even eventually etch into the glass and become much more difficult to clean. There are a few steps you can take to prevent the stains in the first place.

Since sprinklers are the main culprit of hard water stains on exterior house windows, ensure that your sprinklers aren’t spraying the windows. If your windows already have hard water stains, hydrofluoric acid can remove them. However, it is recommended to allow an experienced professional to handle this acid. In the case that the stains are too permanent to be removed with acid, the windows will require restoration. 


If you need professional window cleaning for your house, reach out to Charity Window Cleaning in West Haven, UT. With their attention to detail and innovative M3 cleaning technology, their team will leave your windows squeaky clean and residue-free. In addition to window cleaning, they offer exterior house washing, concrete sealing, and power washing. Call (385) 336-0329 to speak with a team member, and visit them online to learn more about their services.