How to Clean under Toilet Rim Stains

As it’s a damp, difficult place to get to, under the rim of your toilet can be one of the most challenging places to get clean. There can be all sorts of unpleasantness hidden under there, such as mold, discoloration from water, and bacterial strains. While it’s not usually visible to the naked eye, you may still want to have this area clean to avoid further buildup. 

There are many DIY and professional-grade solutions available, such as chemical cleaning liquids and syringes, to get rid of blockages and buildup that appears. Whether your toilet requires a deep or heavy clean depends on the age and type of stains present. If there is only a light level of staining, there are some easy homemade options available. For those more challenging to clean problems, it will be necessary to use more serious chemicals. 

As the problems created can significantly increase the bacteria levels in your bathroom, it is worth getting on top of these issues sooner rather than later. In this article, we’ll take a look at some steps you can take to fix all manner of issues that appear under the rim of your toilet. 

Ways to Fix Under the Rim Dirt Buildup 

Below is a list of products and chemicals you can use to clean a range of stains, dirt, and general nastiness: 

  • Mineral deposits or limescale – Put half a cup of baking soda into your toilet, let it settle, and then flush with vinegar. Coca-Cola is also a viable solution in this case. 
  • Mildew/Mold – Household bleach could be an easy option here or any heavily chlorinated liquid. 
  • Bacteria buildup – Using borax or borax paste could be the best answer, or try vinegar, hydrogen peroxide, or lemon citric acid. 

Try using a range of these options in combination, as it may be a mixture of the problems above that need to be solved. 

Disinfect and Scrub 

The first step to clean under the rim is to first apply disinfectant such as bleach or vinegar before spraying with a simple store-bought cleaner and giving a good scrub. 

Let’s take a look at some more methods for cleaning under the rim: 

Solve Limescale Problems with Vinegar and Duct Tape 

You will need: 

  • A household mirror 
  • Toilet brush 
  • Tape 
  • Old rags that can be thrown away 
  • Bucket 
  • Gloves
  • Vinegar 


  • Turn off any water access to the toilet. 
  • Using the brush, remove as much water as possible from the toilet bowl, giving you the space needed to clean underneath.
  • You will also need to check that no water is dripping through the toilet system. 
  • Once the toilet bowl is as dry as you can make it, tape down the bowl so that no liquid will be able to get through 
  • Fill the toilet bowl with vinegar. This will begin breaking down any organic material in the bowl. 
  • Keep the vinegar there for at least an hour, though an overnight soak would be ideal. 
  • Remove the tape, then flush and allow clean water to rush through the toilet. 

Baking Soda and Vinegar 

By mixing these two items, a chemical will be created called carbonic acid. As the name implies, this is a heavily acidic chemical that will help to break down mold and buildup that has appeared around your toilet rim. 


  • Take a cup of vinegar and place it in your toilet bowl. Mix around with a brush so that all of the bowls are soaked. 
  • Let this settle in the bowl for 30 to 60 minutes. 
  • After letting the vinegar settle, pour in a generous amount of baking soda. The vinegar you have swished around will ensure baking soda sticks to the sides and parts of the bowl you want to clean. 
  • Let the items combine and fizz for about 15 minutes. At this time, use a brush to clean all areas of the toilet, of course focusing under the rim. 
  • Rinse off by flushing. The toilet should now be much cleaner! 

Borax and Vinegar  

While borax can be hard to find, it should be available at your local hardware store. It’s a more heavy-duty cleaner that can work well on tougher stains. This method combines it with vinegar for a 1-2 punch. 


  • Measure out a cup of borax and pour it into the bowl. (Careful as this is a more dangerous cleaning product) 
  • After a short moment, pour vinegar over borax
  • Give the toilet a light scrub
  • After 15 minutes, flush the toilet and scrub again, focusing on underneath the toilet rim. 

Borax Paste 

If the above steps have not worked, the borax paste is another heavy-duty option worth trying on stubborn stains. 


  • Give the toilet bowl a preliminary scrub, so mold is clearly visible. 
  • Combine borax and a small amount of water to create a paste, which needs to be thick enough to coat toilet walls. If the paste is too watery, add more borax.
  • Smear the paste over heavily affected areas, leave for a moment and scrub gently, ensuring all areas are covered. 
  • Let the paste set for 30 minutes.  
  • Scrub paste gently to remove stains, then flush again. 

For this method, water can also be replaced with vinegar for a potentially more effective solution. Whether you’re using vinegar or water, remember only a small amount is required. 

What is This Stuff underneath My Toilet Rim? 

As stated earlier, the underside of your toilet rim is where many problems can occur. Staining and dirt is in this area is usually the result of one of these issues: 

  • Mold – This is likely the issue, as mold thrives in dark and damp areas. Since this occurs under the rim of your toilet, there is a good chance buildup will occur without you noticing 
  • Bacteria Buildup – A specific bacteria can grow in this area of your toilet, called Serratia Marcescens. This bacteria is the culprit if you are noticing pink stains under the rim. 
  • Mineral deposits – If you are noticing heavy brown, black, or bronze stains forming rings or making their home at the bottom of your toilet, this is probably the issue. It is usually caused due to toilet jets. 

Vinegar and baking soda is the best solution for any mineral deposit issues. For mold and bacteria, try the steps already mentioned above. 

I’ve Tried These Methods and Nothing Works! What’s Next? 

If you’ve tried all of these homemade options and still do not have a clean toilet, it’s time to use some commercially sold cleaners. But beware! These cleaners are not designed for all types of toilets and could end up creating further damage. Check with the toilet manufacturer to see what can be safely used with your toilet. 


A pumice cleaning stone is generally safe to use on porcelain bowls. It is reusable and works well to solve rust and limescale buildup. This is a very safe option that is ideal if you have pets or children.

Although it is usually safe on hard stains, be careful not to overuse the pumice stone as it can create wear on the toilet surface. 

Iron Out Automatic Toilet Bowl Cleaner 

According to reviews, this is one of the highest-rated cleaners for solving under the rim problems.

If used correctly, this product can get rid of those heavily caked in stains and prevent rust from appearing in your toilet bowl. 

To use, simply clean your toilet bowl with the product, then insert a tablet into your cistern. This product is safe to use on all toilet and sewage systems. 

Bio Clean-Eco Friendly Hard Water Stain Remover 

Those looking for an environmentally friendly option may be reluctant to use some of the heavy-duty chemicals mentioned. If that’s you, consider trying Bio Clean Hard Water Stain Remover, as it is made from organic chemicals that are considered safe for the environment and your family. 

Unlike most cleaners, you do not need to combine this with water. Simply apply directly onto the stains and mold present in your toilet, and use a clean, dry cloth to remove. 

Clorox ToiletWand Disposable Toilet Cleaning System 

If you are having issues with bacterial stains in your toilet, try the Clorox cleaning system. This product contains scented refills and a toilet wand that can be used to clean out your toilet bowl simply and effectively. 

This product can be used without requiring the purchase of other scrubbing brushes or other cleaning items. 

Power Drill Brush Scrubber 

As you can imagine, this is a very heavy-duty item to get rid of stubborn stains and mold! 

While relatively new on the market, these products can quickly get your toilet clean and are very satisfying to use. 

Recurring Stains Under Rim 

If you are having trouble with stains appearing in your toilet after you have cleaned it, it’s highly likely that there is a mildew problem in your toilet tank. 

To solve this, simply open your toilet cistern and take a look. If black deposits are visible, this can be solved easily with bleach and vinegar. 

Maintaining a Clean Toilet Bowl 

As you can see from the information above, there are plenty of ways to have the rim of your toilet bowl clean. However, the best method is always prevention. To keep your toilet clean year-round, follow these steps: 

  • Consistently clean your toilet bowl to prevent the build-up of stains and mold. 
  • Make sure there is enough ventilation. Remember that mold loves a damp area!
  • Replace old toilet bowls, as stains can develop easily on cracked and worn surfaces. 
  • Leave your toilet lid up. Problems usually occur in dark, moist areas, so keeping the toilet lid up will mean airflow can get through to your toilet and make it an environment where stains, mildew and mold are not welcome.