Sunrise Specialty » What Causes Grey Stains in a Toilet Bowl? (Tricks to Remove)

What Causes Grey Stains in a Toilet Bowl? (Tricks to Remove)

Unfortunately, toilets are magnets for stains of all kinds, and as much as you might hate doing cleaning them, if you don’t keep on top of it, they can quickly get out of hand.

Grey stains can appear on the sides of toilet bowls or form rings at the water line, but fortunately, they’re not too hard to get rid of – and to help you, here we discuss what causes grey stains in a toilet bowl as well as giving you some tips and suggestions for removing them.

What Causes Grey Stains in a Toilet Bowl?

Although you can treat most stained toilets with similar cleaning agents regardless of what caused the problem, it’s useful to think about where the stains come from.

This is because knowing why they occur can help you prevent them from appearing in the first place – or from coming back after you’ve cleaned them off.

Here are the main culprits for gray stains in toilet bowls:

1. Limescale

Probably the number one cause of gray stains inside a toilet bowl is a mineral deposit from hard water, also known as limescale.

When water falls from the sky as rain, it is “soft” – that is, it doesn’t contain any minerals.

However, as it passes through rocks like limestone on its way to our water supply, it picks up various minerals like calcium, magnesium and iron, which makes it “hard”.

Then, when we use this water in our sinks and toilets, the minerals can slowly build up and solidify, leaving a dirty-looking deposit.

This can appear as a vertical stain in the toilet bowl where the water runs down, and it can also show up as toilet rings around the water line.

These stains can often be gray, but they can also be other colors such as brown, yellow or even black.

2. Bacteria

Another common cause of stains in toilet bowls and elsewhere in bathrooms is bacteria, most often Serratia marcescens bacteria.

This kind of bacterium can cause pink or orange marks to develop that may turn gray or black with time.

A damp, dirty toilet is the ideal breeding place for bacteria, so the best defense against bacterial stains is to ensure your toilet is always kept clean.

3. Mold and mildew

Mold and mildew can also cause gray stains or stains of other colors to appear in toilets. This will usually happen in toilets that aren’t used often and aren’t regularly cleaned.

As with bacteria, toilet bowls provide the perfect environment for mold and mildew to thrive, so the best way to prevent this kind of problem is to make sure your toilet is cleaned regularly.

What can you use to get rid of gray stains in Toilet Bowl?

When you notice gray stains developing in your toilet, you can use regular store-bought toilet cleaner, but these can be expensive as well as harmful to the environment. However, there are some gentler, less expensive options available too, so let’s have a look at these now.

1. Vinegar

Among the most popular cleaning agents for all kinds of household chores is vinegar. It contains acetic acid, which is a powerful cleaner and stain remover, but despite its potency, vinegar is not harmful to the environment.

In a pinch, you can use the kind of vinegar intended for food because the results will be the same. However, it’s better to always have a bottle of cleaning-grade white vinegar in the house anyway because it’s so useful and because it’s cheaper.

2. Bicarbonate of soda

Bicarbonate of soda, sometimes also known as baking soda, is another useful cleaning product that all homes should have in a cupboard somewhere.

Again, like vinegar, it’s better to buy cleaning-grade baking soda rather than food-grade powder since it costs less.

3. Lemon juice and essential oil

An alternative to vinegar is lemon juice, and this works for a similar reason. This time, the active ingredient is citric acid, which does the same job as the acetic acid in vinegar.

Another advantage is that lemon juice has a pleasant odor that is preferable to the pungent smell of vinegar.

If you mix lemon juice with a few drops of essential oil, it will be even more effective – and it will smell even better.

4. Coke

Coca-Cola is a famously useful home remedy for tasks like cleaning toilets and sinks as well as unblocking them. This is because it is mildly acidic, and the fizzing caused by the carbonation also helps shift stains and break up blockages.

If you’re a fan of Coke and don’t want to waste it by tipping it down the toilet, cheaper generic colas will usually work just as well.

5. Borax

Borax is a kind of powder that’s similar in some ways to bicarbonate of soda. However, harsh chemicals like this are not available in regular supermarkets or grocery stores, so you’ll need to pick it up from a specialist hardware store.

You can simply sprinkle it onto stains, or you can use it to make a paste – as we’ll see in just a moment.

6. Bleach

Chlorine bleach is an extremely effective stain remover, but it’s another harsh chemical, so you should only use it as a last resort because it’s harmful to the environment and can also damage your skin and eyes if you’re not careful.

Also, bear in mind that bleach is ineffective for the removal of hard water deposits – although it may help get rid of stains left after the mineral deposit has been removed.

Always wear rubber gloves when working with chlorine.

How to get rid of gray stains from your toilet bowl?

How to get rid of gray stains from your toilet bowl?

If you notice any gray stains or any other colored marks in your toilet bowl, here are some suggestions for how to remove them.

First, remove the water from the bowl

If your toilet develops a gray ring around the water line, you will need to remove the water from the bowl before you can clean it – and even if the stain is elsewhere, removing the water first will usually make the job easier.

To do this, all you’ll need is an old cup or ladle and an old towel. Simply use the cup or ladle to scoop out as much of the water as possible from the toilet – then use the towel to soak up whatever remains.

Note that if the discoloration is around the rim, you might not need to empty the toilet bowl before cleaning it.

What to do next

Here are a couple of suggestions for cleaning methods you can try for removing gray stains from your toilet bowl.


How to get rid of gray stains from your toilet bowl with vinegar

What you’ll need:

  • Vinegar
  • Spray dispenser
  • Toilet brush

Step 1. Scrub with the toilet brush

After removing the water from the toilet bowl, start by scrubbing the stain with your toilet brush. It probably won’t remove the stain completely, but it should help remove some of it, especially if the stain is due to a mineral buildup.

Step 2. Spray the vinegar onto the stain and leave it to act

Pour a cup of vinegar into the spray dispenser and spray the vinegar generously over the stain.

You then need to leave if for at least half an hour – or longer if possible – for it to take effect.

Step 3. Scrub again with the toilet brush

After the vinegar has been left for long enough to do its work, scrub again with the toilet brush. This time, you should be able to remove the stain completely.

Step 4. Flush the toilet to wash away the vinegar

When you have scrubbed the stain off, simply flush the toilet once to fill the bowl and then flush once more to rinse the vinegar and dirt down the drain.

Inspect the stain to see if any remains, and if you’re not happy with the results, repeat the process once or twice more.


How to get rid of gray stains from your toilet bowl with bicarbonate of soda

What you’ll need:

  • Bicarbonate of soda
  • Old cup for mixing
  • Spatula or old spoon
  • Toilet brush

Step 1. Scrub the stain with a toilet brush

After emptying the toilet bowl, give the stain a preliminary scrub with the toilet brush as above. Again, don’t expect to remove everything – but you should be able to remove some of the worst of it.

Step 2. Mix up a paste of bicarbonate of soda and water

Using a ratio of 2:1 bicarbonate of soda to water, mix up a paste in the cup.

Step 3. Apply the paste to the stain and leave it to act

Use the spatula or old spoon to apply the bicarbonate of soda paste to the stained area. Leave it there for at least half an hour or preferably longer to take effect.

Step 4. Scrub again with the toilet brush

Take the toilet brush and scrub the stain. When you take off the paste, you should find that a bit more scrubbing will remove whatever’s left of the stain.

Step 5. Flush twice and inspect, repeat if necessary

Flush the toilet twice to get rid of the bicarbonate of soda paste and any residue that has been removed. Inspect the toilet and repeat the process if the stain hasn’t completely gone.

Other suggestions

These methods with vinegar or bicarbonate of soda are the basic techniques you can use to remove gray stains from your toilet bowl. However, there are other variations you can try if these don’t quite work as you hoped.

One option is to use vinegar instead of water when you mix up the paste of bicarbonate of soda. Use the same 2:1 ratio.

You can also try mixing up a paste with borax powder and water – with the same ratios – or even a paste of borax and vinegar.

Lemon juice and essential oil can also be sprayed onto stains like vinegar in Method 1.

Coca-Cola is not such a useful option for stains on the sides of a toilet bowl or stained rings around the water line.

However, if the stain is at the bottom of the toilet, once you have removed the water, you can pour in a bottle of Coke and leave it to sit for half an hour or more to allow it to dissolve the stain.

As we said, bleach is not good for removing mineral deposits, but once the mineral deposit has gone, you can use bleach to help return the toilet to its original color. Read the instructions on the bottle or package carefully before using.

More tips for the best results

Here are a couple of other tips that will help you beat those gray stains when they appear – and keep them under control.

1. Don’t use abrasive brushes

However tempting it might be, it’s important that you don’t use abrasive brushes to clean your toilet bowl or toilet seat.

If you use something abrasive to scrape away the stain, you are also likely to scratch and damage the porcelain of your toilet bowl or the plastic of the seat.

Then, once a toilet is damaged in this way, it makes it easier for all kinds of stains to take hold again, which will mean you’ll end up cleaning them off much more frequently.

Similarly, avoid using pumice stones. Many people will tell you they are a good option, but they are abrasive, so you’ll risk damaging your toilet.

2. Keep to a regular cleaning schedule

The best weapon against stains of all kinds is to stick to a regular cleaning schedule to ensure your toilet never develops issues – and even if it does, you’ll be able to deal with them before they become too bad.

3. Check the cistern for bacteria or other problems

If you find that stains keep reappearing, it could be that you have a problem with the toilet’s tank. Sometimes, bacteria can breed in there, there could be a leak causing mineral buildups to happen more quickly or something could have rusted.

If you find bacteria growing in the cistern, remove the water and clean the tank with vinegar, and if you find a leak, make sure it’s repaired. These small actions should help prevent the stains from coming back quite so quickly the next time.

Note that if you discover rust in the cistern, it could indicate rusted pipes, in which case it might be a good idea to call out a plumber to check.

4. Use these techniques for other cleaning jobs

Many of these cleaning agents can be adapted to clean dirt and grime from other areas of your bathroom, like bathtubs, basins, showers, tiles, grout and more.

Unsightly and unpleasant – but not a huge problem

Although they might be unwelcome and unpleasant, gray stains usually aren’t too hard to get rid of using a few basic household items – and if you follow the methods we’ve outlined in this post, you can look forward to seeing clean toilets in your home in no time.