How to Remove Hard Water Stains From Glass

Use Distilled White Vinegar

Distilled white vinegar is a mild acid (acetic acid) that will help break the bonds the hard water minerals have formed with the glass surface. You can also substitute fresh lemon or lime juice (citric acid) in the cleaning solution.

1. Mix a Cleaning Solution

   In a spray bottle, combine one part of distilled white vinegar or lemon juice with one part of distilled water.

   Tip

   For a stronger cleaning solution, use cleaning vinegar instead of food-grade distilled white vinegar. Cleaning vinegar contains around 6 percent acetic acid while food-grade contains around 5 percent acetic acid and 95 percent water. That doesn't sound like much of a difference, but cleaning vinegar is 20 percent stronger than white distilled vinegar for tackling cleaning chores.

2. Spray on the Solution

   Place an old towel at the bottom of the glass panel to catch drips. Starting at the top of the glass shower door or window, spray the vinegar and water solution across the top of the glass. Move down methodically in even rows until every part of the glass is wet.

   Allow the solution to remain on the glass and work for at least 30 minutes.
   

3. Scrub and Wipe Away the Mineral Deposits

   Using a soft-bristled brush or microfiber cloth, start at the top of the glass panel and wipe away the mineral deposits. Work in a circular motion and rinse out your brush or cloth often. Use an old toothbrush to get into corners or around the edges of metal trim.

   While vinegar is non-toxic, wear rubber gloves to protect your hands and eye protection to avoid splatters to the eyes.
   

4. Rinse and Dry

   Once the hard water stains have been loosened and removed, rinse the glass with fresh water. Starting at the top, use a good quality squeegee like the one from Libman to remove most of the water. Finish drying completely with a lint-free microfiber cloth.
   

Use Distilled White Vinegar and Baking Soda Paste

If vinegar alone did not remove the spots caused by hard water, add baking soda as a gentle abrasive. This paste also works well on water-spotted drinking glasses and other glassware.

1. Spray the Glass With Vinegar

   Place an old towel at the bottom of the glass to catch drips. Pour some undiluted vinegar into a spray bottle and starting at the top, spray the entire surface of the glass. Let the vinegar work for at least 30 minutes.
   

2. Create a Cleaning Paste

   In a small bowl, mix one part of water with three parts of baking soda to create a thin paste. It is usually best to mix the paste in small batches so the paste is not too watery.
   

3. Apply the Paste

   Using a cloth or scrub brush, apply the paste to the hard water-stained areas of the glass. Rub it on in a circular scrubbing motion and always start at the top of the area that needs cleaning and work your way down. If there are only a few stains, dip an old toothbrush into the paste and use it for scrubbing.

4. Spray With Vinegar Again

   After you have applied the paste and it has dried slightly, spritz the area again with undiluted vinegar. You should see some foaming as the baking soda and vinegar react to each other.
   

5. Rinse and Dry

   When the foaming stops, rinse the glass with clean water and dry with a squeegee or microfiber cloth.
   

When to Call a Professional

If your home's exterior windows are riddled with hard water stains and it's tough to reach them, it may be time to call in professional window cleaners. They will be able to get rid of the stains in the safest and most efficient manner.

Additional Tips for Handling Hard Water Stains

• After showers or when cleaning any type of glass, dry the surfaces completely to prevent hard water spots from forming.
• Use a diluted vinegar solution for weekly cleaning to keep deposits from building up.
• Move sprinklers away from windows to prevent hard water stain splatters.
• Apply water-repellent products to help water sheet off quickly from glass.