How to Remove Hard Water Stains
Here's what causes these pesky hard water stains, plus the very best tips on how to remove them from tubs, toilets, glass, and dishes.
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Hard water stains may be a burden, but they’re not permanent—there are many unusual ways to remove hard water stains that actually work. Whether there’s a hard water stain on your glass shower doors or you’re dealing with hard water stains in the toilet, these smart tips for how to remove hard water stains—plus, advice on how to prevent them—will help you keep water stains gone for good.
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What is hard water?
According to the U.S. Geological Service, water hardness is defined as “the amount of dissolved calcium and magnesium in the water.” Put plainly: “Hard water is high in dissolved minerals, largely calcium and magnesium.”
Hard water isn’t bad for your health, so there’s no need to panic—but hard water make soaps less effective, so you’ll have to use more product to get the same results.
Also, hard water leaves “stains” (aka traces of minerals) behind. “Hard water stains are high in minerals, which then leaves behind a chalky residue on surfaces,” explains Rosa Nogales-Hernandez, head of home cleaning at Valet Living.
These hard water stains are not permanent; however, if they’re allowed to build up over time, you could end up with layers of scale in your bathroom plumbing or around the valves of your dishwasher which could lead to costly repairs down the line.
What causes hard water?
When rain and natural groundwater travel through layers of rock and soil, they dissolve and pick up hints of different water-soluble minerals—namely calcium and magnesium—as they go.
Depending on the soil content where you live, your water may be harder or softer. Here’s a map from the National Water-Quality Assessment (NAWQA) Project showing how water hardness levels vary across the United States.
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How to tell if you have hard water
Water is measured on a “water hardness scale”—this scale ranks how hard or soft water is based on how many milligrams of calcium are found in one liter. So, to know if you have hard water or not, you’ll have to find out how many milligrams of calcium are in one liter of water.
The scale ranks water hardness from soft, on the low end, to very hard, on the high end:
- Soft: 0 to 60 mg/L
- Moderately hard: 61 to 120 mg/L
- Hard: 121 to 180 mg/L
- Very hard: 180 mg/L and up
There are plenty of ways to test your water hardness at home:
- You can buy a kit on Amazon, like these highly-rated Total Water Hardness Test Strips by Just Fitter.
- You can call your local utility company and ask for the latest data. They’ll be able to tell you what the water hardness levels are in your area.
- You can check dishes and glasses as soon as they come out of the dishwasher. If there’s cloudiness or spots on them, you have hard water.
- Pay attention to how it feels when you wash your hands. If it feels like there’s a soapy or filmy residue you have to keep scrubbing to wash off, you have hard water.
- You can put 10 drops of liquid dish soap into a half-filled bottle of water and shake it up. If only a thin layer of suds form (vs. a whole lot), you have hard water.
What to do if you have hard water?
Installing a water softening system is your best long-term solution. These systems filter your home’s water before it comes into your home. During the filtration process, negatively charged particles in the filtration system attract the positively charged calcium and magnesium ions so they get removed from your water.
There are plenty of different types of water softening systems to choose from:
However, since hard water isn’t harmful to your health, springing for a $400 to $500+ system may not be your top priority. If that’s the case, you may just need to use a little extra soap or detergent to get things clean.
Best hard water stain removers
Hard water stains aren’t permanent, but they can be stubborn—so using non-toxic hard water stain removers to get the job done can help.
Here are the most effective home remedies and products for removing hard water stains, according to cleaning pros:
Hands-down, a simple white vinegar and water mixture is the best hard water stain remover, according to cleaning pros.
“I have found that spraying a mixture of white vinegar and water onto the stained area, letting it sit for 15 minutes, then wiping it away will usually get rid of a hard water stain,” Nogales-Hernandez says.
For especially tough hard water stains, give your white vinegar mixture a little boost by sprinkling some baking soda on top.
A baking soda paste—made by adding a few drops of water to baking soda and mixing it until it for—can help scrub away hard water stains.
Apply it directly to the hard water stain, let it sit for a few minutes, then use a bristled brush to gently scrub away the stain. Flush the area with water.
Kaboom Foam-Tastic with Oxiclean
“For my home, I use Kaboom Foam-Tastic with the power of Oxiclean,” Nogales-Hernandez says. “It works wonders on soap scum, hard water build-up, lime stains, calcium deposits, and even grease so it takes the place of many different products, freeing up more cabinet space!”
To use, spray it on the hard water stain and let sit until the formula turns white. Then, wipe it—and the stain—right off.
A mixture of borax and vinegar will remove just about any hard water stain—but it works especially well on toilet bowls.
You can combine vinegar and borax to make a paste that can be applied to hard water stains around the bowl’s edges directly, or you can pour it right into the toilet bowl and let it sit before scrubbing.
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Hard water spots on glassware and dishes
Removing hard water spots on glassware and dishes is actually quite simple. There are two main methods to try and both involve white vinegar:
Method 1: A simple way to prevent hard water spots on dishes and glassware: “Use white vinegar as a rinsing agent,” Nogales-Hernandez says. Just pour the vinegar into your dishwasher in place of your normal rinse agent and you’ll be good to go.
Method 2: If you don’t have a designated spot for rinsing agents in your dishwasher model, you can put a bowl filled with vinegar on the top rack and run the load like normal—it works the same way.
Iuliia Mikhalitskaia/Getty Images
Hard water stains on showers and tubs
To get rid of hard water stains on showers and tubs, a mixture of vinegar and water will do the trick, says Nogales-Hernandez. Follow these steps:
- Mix white vinegar and water in a spray bottle.
- Spray the mixture onto the stained area.
- Let is for 15 minutes.
- Wipe away with a cloth.
Hard water stains on faucets and showerheads
For tricky spots like faucets and showerheads, try this hack so you can clean them without having to remove the faucet or showerhead first:
- Create a white vinegar and water mixture.
- Dip paper towels into the mixture, and gently squeeze so they’re not dripping.
- Wrap the paper towel around your faucet or showerhead, and let sit for 15 minutes.
- Remove paper towels and use them to wipe the stains away.
How to prevent hard water build-up in the first place: “Reducing the amount of time that water sits in the tub will reduce the build-up of stains,” Nogales-Hernandez says.
How to remove hard water stains from glass
Learning how to remove hard water stains from glass—whether it’s glass shower doors or glass on your windows—doesn’t take much elbow grease; just follow these simple steps:
Shower glass doors
Here’s how to clean hard water stains from shower doors:
- Mix vinegar and water in a spray bottle.
- Spray the mixture liberally all over the doors, starting at the top and working your way toward the bottom.
- Let sit for 15 minutes. You may need to reapply more of the vinegar-water mixture at the halfway point since the solution runs down the doors.
- Finish by using a cloth to wipe away the hard water stains.
To make things easier on yourself next time: “Having a shower squeegee to use after each shower will do wonders for the glass doors,” Nogales-Hernandez says, “and it only takes a minute to do!”
When hard water stains are on windows, take these steps to get them clean and clear once again:
- Combine vinegar and water in a spray bottle to create a homemade cleaning solution.
- Spray the mixture onto the window, and allow to sit for 15 minutes.
- Wipe away the hard water stains with a soft cloth for a streak-free shine.
How to remove hard water stains from toilet
If you want to try a product specifically geared toward toilet bowls, Nogales-Hernandez suggests Lysol Power Toilet Bowl Cleaner because it easily breaks down hard water stains.
- Apply a generous amount of Lysol Power Toilet Bowl Cleaner around the rim of your toilet bowl.
- Let the cleaner drip down so it covers all of the hard water stains, and apply more if needed.
- Let sit for 15 minutes before wiping clean.
“If there is still a stain there, get that white vinegar-water mixture, spray it on the stains and let it sit for 20+ minutes,” Nogales-Hernandez says. “Then, hit the stain with the toilet brush and flush the stains away.”
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General tips on removing hard water stains
These basic tips on how to remove hard water stains will help you keep mineral build-up in check:
- Don’t let excess water sit. The faster you can wipe up any drips or pools of water, the more likely you are to avoid stains.
- Keep a bottle of white vinegar handy. When mixed with water, this DIY home cleaning solution works on all types of hard water stains.
- Don’t rush it. Whether you’re using vinegar, baking soda, or a cleaning product you bought on Amazon, let the cleaner sit for 15 minutes (you can go up to 20+ for extra tough stains) so the chemicals have time to work their magic. More patience now equals less scrubbing later.
- Use vinegar and water-soaked paper towels for tricky spots. It’ll make it easier to tackle detailed or drip-prone areas, like showerheads and faucets.
- Install a water filtration system. Hard water isn’t a health risk, but this is the only thing that will truly keep hard water stains from coming back.
- Rosa Nogales-Hernandez, head of home cleaning at Valet Living
- USGS.gov: Hardness of Water