How to Remove Hard Water Stains from Glass

Say good-bye to the grime on your glass.

Hard water stains are frustrating to deal with, especially on glass surfaces. The spots can cause the glass to become hazy and cloudy in appearance.

But what causes hard water stains? They occur when hard water is evaporated from a surface, leaving mineral deposits behind. These minerals can also cause limescale and other buildup within pipes and appliances, such as water heaters and dishwashers.

Even though prevention is the best solution, we all lead busy lives. We’ll show you how to remove hard water stains from glass quickly, even if you’re pressed for time.

Shower Doors

At first, leaving hard water on shower doors doesn’t seem like an issue. However, if left, the resulting stains can really start to look unsightly.

We have two methods for you to remove the hard water stains here:

  • White vinegar.
  • Acidic cleaner.

Method 1: Vinegar

White vinegar is a popular choice since it’s a more natural solution, and less toxic. Plus, many people already have it in the home, making for a cheap and convenient solution.


Be careful if you have hardwood and stone flooring. White vinegar shouldn’t be used near these surfaces; its acidic properties can damage the finish (1). If you have any other type of flooring, vinegar is safe to use.

What You Need

Before you’re ready to clean, make sure you have these to hand:

  • Clean cloth.
  • Spray bottle.
  • Sponge.
  • Microfiber cloth/towel.
  • White vinegar.
  • Baking soda.

Step 1: Clean the Glass

Start by wiping the door with a damp cloth to get rid of any potential dust or dirt particles. This will make it easier to remove the stains and avoid streaks in the end.

Step 2: Mix Your Solution

Combine equal parts of water and vinegar in a spray bottle. If the stains are harder, you can add more vinegar than water to make the solution more potent.

Because hard water is alkaline, an acidic cleaner, such as distilled white vinegar, is highly effective at dissolving the minerals. The acids neutralize the alkalinity and dissolve the stains (2).

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Step 3: Apply the Solution

Spray the solution onto the obvious stains and then spray the entire door. Allow it to sit for five minutes to let the vinegar get to work. You’ll notice that most of the solution will drip down the glass; however, some will stick to the stains.

Apply the solution to a sponge and wring out the excess, leaving it damp. Use it to smear the vinegar solution all over the door. Pay close attention to lower corners and close to the rim — these are common areas of buildup.

Step 4: Make a Paste

Make a paste using equal amounts of baking soda and white vinegar. Dip a sponge in the mixture and apply using circular motions.

Step 5: Rinse

Rinse the door off using warm water. You can use the showerhead for this. If you notice a few stubborn stains, use the sponge to give it a quick scrub while rinsing.

Step 6: Dry the Glass

After cleaning and rinsing, you must dry the glass using a cloth (preferably microfiber as this won’t streak). Drying the door is crucial to prevent new stains from forming. If there’s still significant staining, repeat the above steps.

Take Note

This method works well on mirrors too!

Method 2: Acidic Cleaner

If using white vinegar isn’t an option, or you have severe hard water stains, consider using an acidic cleaner.

What You Need

  • Personal protection equipment — rubber gloves, plastic apron, and mask.
  • Acid solution — hydrochloric, sulfuric or phosphoric acid.
  • Spray bottle.
  • Clean cloth/sponge for application.
  • Clean cloth/towel for drying.

Step 1: Get Protected and Ventilate

These acids are highly abrasive and can cause substantial damage to your skin if exposed. They can also produce toxic fumes, so stay protected and wear thick rubber gloves, a plastic apron, and a mask. Keep the room ventilated (3).

Protect Your Floors

If you have natural stone flooring, cover it in plastic to avoid damage. Even a natural acid like vinegar can etch natural stone tiles (4).

Step 2: Choose a Product

For a heavy buildup of hard water stains, you’ll need something stronger than vinegar. Choose a strong acidic product such as hydrochloric, sulfuric or phosphoric acid. These are very strong and will be able to break down the minerals.

Step 3: Use as Directed

Dilute the product as directed on the label. An excellent way to do this is by filling a spray bottle — this will make the application more manageable as well. Allow the product to sit if needed, or wipe off immediately with a cloth or sponge.

Step 4: Rinse and Dry

Rinse thoroughly with clean water once you’re done. Any residue left behind can cause damage in the long run.

Don’t forget to dry the glass after rinsing to prevent more buildup.

Glass Windows

Again, we prefer the white vinegar method here. A chemical product should be used as a backup.

What You Need

  • White vinegar.
  • Salt.
  • Baking soda.
  • Mixing container.
  • Spray bottle.
  • 2 x Clean cloth/sponge.
  • Clean microfiber cloth.

Step 1: Apply Vinegar

Use a spray bottle to apply equal amounts of water and vinegar onto the stained window. Smear the solution around using a damp cloth or sponge. Allow it to sit for up to 30 minutes.

If the stains are particularly hard or stubborn, use undiluted vinegar.

Step 2: Make a Paste

Combine equal amounts of salt and baking soda in a container or bowl, then add small amounts of water to form a paste. You can use any salt for this, but fine table salt is typically easier to work into a paste.

Step 3: Apply the Paste

The combination of baking soda and salt will create a mildly abrasive cleaner that will cut through the tough stains.

Dip a cloth or sponge in the paste and rub it onto the window using circular motions. You don’t have to apply too much pressure since the baking soda and salt will do most of the work.

Step 4: Rinse and Dry

Rinse the area well using a damp sponge or cloth. Try to get all of the paste off to avoid stains.

Finish off by polishing the window using a clean microfiber cloth.

Drinking Glasses

Method 1: Vinegar

What You Need

  • White vinegar.
  • Distilled water — or tap water if you can’t get distilled.
  • Spray bottle.
  • Clean dishcloth/towel.
  • Clean two-sided sponge.
  • Clean microfiber towel.

Step 1: Mix Vinegar and Distilled Water

Start by combining equal parts of water and white vinegar in a spray bottle. You can use tap water if you don’t have distilled. However, distilled water is pure and free of any hard materials such as minerals, so it won’t cause new stains (5).

Step 2: Set up the Glasses

Place a folded dish towel or cloth on a flat surface. Place each glass on the towel — if spots are on the inside, keep the glasses upright for ease of access.

Apply the solution by spraying all over the spots. Leave them to sit for a couple of minutes.

Step 3: Scrub

Use the soft side of a two-sided sponge and wet it with the vinegar solution. Scrub the stained area gently to remove the mineral deposits. If the stains are stubborn, turn the sponge over and wet the rough side — scrub the area again.

Step 4: Rinse and Dry

Rinse the glasses thoroughly once the stains are gone. Give them a quick shake over the sink to get rid of excess water, then wipe to dry using a clean microfiber towel.

Method 2: Dishwasher

  • Temperature: If you often notice hard water stains on your clean glasses, the problem could be coming from your dishwasher. To solve this issue, you can start by lowering the temperature of the water. This will not only be better for the environment, but it will also prevent minerals from forming scale. High temperatures harden minerals and form scale — look at your kettle after boiling water (6).
  • White vinegar: Another way to combat hard water stains is by adding ¼ cup of white vinegar to the rinse cycle. Open the compartment right before the rinse cycle begins and pour in the vinegar. The acid will break down hard minerals and prevent them from staining (7).
  • Rinsing agent: A third way to avoid hard water stains is by adding a rinsing agent — such as Finish Jet-Dry — to the dishwasher. These are automatically released during the rinse cycle and help the dishes to dry without stains.

Glass Fish Tanks

If you’re a budding aquarist, here are some tips for you:

  • Avoid hard water: It’s generally not recommended to use hard water in the tank due to hard minerals. Experts say that it takes the longest time for fish to adapt to hard water. Also, as the water slowly evaporates, it leaves behind limescale or mineral buildup (8).
  • Don’t use chemicals: Try to resist the urge to clean the stubborn stains with cleaners that you usually use around the house. These can leave a lethal residue to fish — even on the outside of the tank. It’s a good idea to use products recommended by your local pet shop.
  • Vinegar works: If you want to clean your fish tank using a green method, vinegar is perfectly safe to use. It’s highly effective at removing stubborn limescale, and it’s also a natural disinfectant. However, for this method, you’ll need to place your fish into a holding tank first. Drain and empty the tank and scrub the tank and any decorations with the vinegar solution.
  • Algae scraper: You can use an algae scraper or razor blade to scrape off very tough stains. However, avoid using razor blades on plexiglass, as this can cause scratches.

Whenever cleaning a fish tank, make sure you rinse and dry the tank properly before refilling and replacing fish, rocks, and decorations.

Crystal Clear

Hard water stains are mineral deposits left after hard water evaporates. They can be frustrating to deal with, but luckily, they’re easy to remove.

As you may have noticed, we love using white vinegar. The acid cuts through and dissolves hard mineral deposits while being safe for children and pets. However, some stains can be extra tough — these require harder acids such as hydrochloric acids.

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About the Author

Sylvia Jones

Sylvia Jones is a hands-on, DIY aficionado from Indiana. She is passionate about home improvement, gardening, and environmental conservation. In her spare time, you can find Sylvia getting involved in home improvement projects around the house with her husband, or spending quality time out in the yard.