How to Remove Hard Water Stains from a Toilet

Aug 10, 2021 | Bathroom Cleaning, Cleaning, Cleaning Organizing

Hard water can cause havoc with your home, damaging appliances, increasing energy bills, and leaving crummy scum and stains in your toilet and tub.

What is hard water, and why does it stain your toilet? And how do you get rid of hard water stains in the toilet? We’ll look at different ways to remove these gross-looking stains, including how to treat your water to make it soft instead of hard. We’ll also suggest how to prevent future hard water stains and answer some frequently asked questions. 

What is the difference between hard and soft water?

When rain falls out of the clouds, it classifies as soft, meaning it contains low-level traces of calcium or magnesium. But as the water travels over the ground, it starts to pick up minerals, like magnesium, calcium, lime, and chalk, making it hard water. 

These essential minerals give drinking water a better flavor and health benefits. However, soft water will taste saltier because it’s been treated to remove the minerals with higher sodium content. This higher sodium often means soft water isn’t as good for drinking.

According to The Water Quality Association of the United States, hard water has 1 GPG (grain per gallon) of dissolved mineral hardness or more. 

  • Soft water – less than one gpg
  • Slightly hard – 1 to 3.5 gpg
  • Moderately hard – 3.5 to 7 gpg
  • Very hard – 7 to 10 gpg
  • Extremely hard – 10 gpg or more

The best way to determine if your home has hard or soft water is by paying attention during daily chores. Hard water can cause clothes to look dingy and stained, residue and spots on the dishes, and filmy soap scum in the tub – mineral deposit stains. These stains may be orange, white, or blue.

If you have hard water, you may also notice that soap is less lathery during showers, leaving your skin feeling filmy and your hair dull and sticky. 

Causes of Hard Water Stain

When your home has hard water, it can cause mineral stains to collect on your sinks, tubs, toilets, faucets, shower doors and curtains, and windows. 

These stains are a build-up of mineral scales that get left behind as the water evaporates, primarily magnesium and calcium. If you have dirty faucets, clogged showerheads, or white residue, you likely have hard water. 

Over 85% of US homes have hard water, even if they use city water rather than a well. Most municipal water treatments do not do anything to treat water for hardness. So it’s up to individual homes to treat their water systems.

How to Remove Hard Water Stains in Toilet

Leaving hard water stains in a toilet over time can cause damage to the porcelain. And it can cause your toilet to look gross and sloppy. So here are some easy methods for how to remove hard water stains in your toilet.

Supplies/tools needed.

There are numerous cleaning products you can buy from the store to treat hard water stains. However, some types may have better success than others. 

But if you’re looking for ways to remove hard water stains from your toilet without using harsh chemicals, some household ingredients are safer and more effective. You can use things you’ve probably already got on hand, like baking soda, Borax, lemon juice, or white vinegar.

You’ll also need gloves, a scrub brush, and possibly a spray bottle to apply the cleaning solution.

White vinegar

White vinegar is a versatile ingredient that makes for an excellent cleaning product, especially for cleaning toilets. It’s also one of the easiest methods of cleaning.

All you have to do is add three cups of vinegar to the toilet bowl and scrub the stains with a toilet brush to remove them.

Vinegar and Baking Soda

Most households have baking soda and vinegar on hand at all times. These ingredients are two of the most versatile natural cleaning products. When you combine them, they are excellent for treating hard water stains in the toilet.

Start by pouring one cup of vinegar directly into the bowl and stir it around with a toilet brush. Give it one minute to soak, then add in a cup of baking soda, followed by one or two more cups of vinegar. 

The reaction that occurs between these two components will cause bubbles to fizz. Anyone who’s made a volcano for a science fair knows how this looks. Give the solution ten minutes before using a toilet brush to mix the solution around and scrub any problem areas.

Over the next thirty minutes, let the solution soak, giving one or two more swishes with the brush if there are still stains. Then flush the toilet to rinse it clean.

Vinegar and Borax

Borax is another excellent cleaner for treating hard water stains, especially when combined with the cleaning power of vinegar.

For this cleaning method, you’ll pour ¼ cup of Borax into the toilet, then swish the solution around with the toilet brush. Next, add a cup of vinegar to the bowl and allow the mixture to soak for twenty minutes. Finally, use the toilet brush to scrub any stains and flush to rinse the bowl clean. 

Scrubbing with Steel Wool

You can also tackle stubborn water stains by scrubbing the areas with the finest grade steel wool, 0000-grade. Thicker grades can cause scratches to the porcelain. 

And because steel wool is naturally abrasive, you don’t have to use anything with it. But you can use plain water or household cleaners for the best cleaning methods.

Borax Paste

A Borax paste is the best treatment for difficult mineral stains that other methods won’t remove. Before adding Borax paste into the toilet, you have to shut off the fixture shutoff valve and flush the toilet to drain the water. 

Then use a ½ cup of Borax and a bit of vinegar to form a thick paste. Immediately spread this paste onto the stains, coating the areas thoroughly. Make sure you wear gloves to keep your hands protected. 

Because Borax will harden pretty fast, you shouldn’t add the vinegar to form the paste until it’s time to apply. Give the paste fifteen to twenty minutes to sit, and then use a stiff-bristled nylon brush to scrub the paste and stains free. Turn the valve back on and flush the toilet to rinse it. 

Scrub with Sandpaper

You can also use sandpaper to scrub away toilet bowl stains. However, it does need to be extra-fine grit sandpaper if you don’t want to scratch your porcelain. And you have to keep wetting the paper when scrubbing.

Cleaning Stone

Cleaning stones are handy for tough stains along the waterline of the toilet. You can pick up a Clorox Toilet & Bath Cleaning Stone from most retail stores. 

These stones are made with compressed and crushed glass that can scrub mineral deposits off of your porcelain without causing scratches. To use these stones, all you have to do is wet the stone and scrub the deposits loose, then wipe the debris clear. 

You can reuse the stone during each sign of build-up, eventually replacing the rock as it wears down to nothing.


Some people swear by using soda to clean mineral deposits out of the toilet bowl. For this method, you will need to empty the tank, either by turning off the shutoff valve or by keeping the flapper closed after you flush the toilet to keep it from filling up. 

After the bowl is empty from flushing, add a two-liter of cola (or two) into it, filling it almost to the top. 

The soda will need to sit for a while, so the acid has time to eat away at the mineral stains. Some people recommend letting the solution soak overnight. Then you can flush the toilet to rinse it. For any remaining residue, you can use a pumice stone or a stiff brush.

Commercial Chemicals

There are also numerous commercial cleaners that you can use, specifically formulated for treating hard water stains. 

Most of these cleaners are simple to use, requiring you to squeeze the product around the toilet’s rim and let it drip down and set the recommended length of time. Then use a towel bowl brush to scrub the porcelain free of stains. 

Popular cleaning products include Lysol Toilet Bowl Cleaner, Clorox ToiletWand Disposable Toilet Cleaning System, and Lime-A-Way Liquid Toilet Bowl Cleaner. 

Regular Toilet Cleaning

Doing regular cleanings of your toilet is the best way to prevent and treat hard water stains. But during your routine cleanings, you don’t have to rely on harsh chemicals. 

Instead, you can use baking soda, vinegar, or Borax, which will clean the toilet bowl free of hard water stains and work as a disinfectant. Using ¼ cup of Borax during cleanings can also help soften the water, further reducing mineral stains.

Tips for Preventing Future Hard Water Stains

Once you get rid of the hard water stains in your toilet, it’s best to prevent them in the future, so you’re not stuck starting back over at square one. So, try these tips to keep your toilet free of hard water stains. 

  • Clean the toilet weekly
  • Keep the surface clean
  • Upgrade old pipes
  • Install a water softener 

Hard Water Stains in Toilet FAQ

What if hard water issues don’t resolve?

If you don’t treat hard water stains, you can end up with a toilet that gets permanently stained by a mineral build-up. You can also end up with reduced water pressure as the sediment builds up around the holes. 

Does Coke get rid of hard water stains in the toilet?

Coke can treat difficult hard water stains in the toilet, although it may not work as effectively as other methods. You will have to let it soak for a while, likely overnight. 

Does WD 40 remove hard water stains in the toilet?

You can spray WD 40 directly on hard water stains in the toilet to help remove lime and rust deposits. Let the spray soak for a few minutes, and then scrub it with a toilet brush.


There are multiple methods that you can use to remove hard water stains from the toilet. From store-bought commercial cleaners to everyday household items you likely already have in your utility closet, this list covers multiple ways to treat mineral deposit stains, so your toilet looks clean and sanitized instead of gross and sloppy. 


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