How to Clean under Toilet Rim Stains

The underside of your toilet rim might be the dirtiest section of the toilet because it is dark, hidden not easily reachable. In addition to debris, it’s not unlikely to find all sorts of discoloration under the toilet bowl rim from black coats of mold, brown discoloration from hard water, and pink stains from bacteria… This is exactly why you should pay more attention to this area, to ensure it’s regularly cleaned to avoid buildup.

From automatic cleaners with syringes, chemical agents to homemade solutions, there are several methods you can use to aid you to get rid of the dirt and the black nasty residue. Depending on the type and age of dirt and stains under the rim, you can do light or deep cleaning. For light dirt simply use homemade toilet cleaners that contain disinfectants. For stubborn, aged hard stains and mineral deposits, combine homemade solutions and commercial cleaners such as borax.

If you’re looking to get this area cleaned up to avoid health hazards as well as maintain high levels of hygiene, you are in the right place. Following is all you need to know about dirt under the rim and how to get rid of it.

Methods to Clean Under the Rim Dirt &Stuff

A simple breakdown of what cleaning solutions to use for different stains/dirt is right here below;

  • Limescale or hard water mineral deposits – vinegar with baking soda left soaking for some time. Coke is also an excellent cleaning agent.
  • Mold and mildew – bleach and automatic chlorinated liquids can easily sanitize, disinfect, and clean up.
  • Bacteria – citric acid in lemons, vinegar, hydrogen peroxide, and borax/ borax paste.

The best method is to combine several methods together to target all the three possibilities of the black ring under the rim.

Disinfect and Scrub

The easiest method to clean  under the toilet bowl rim,  is to first disinfect the bowl with either bleach or vinegar, then squirt a cleaner around the top of the bowl and finally scrub with a toilet brush.

Bleach or vinegar to disinfect and clean under toilet rim
Vinegar and bleach

Below are other methods for an under-the-rim cleanup.

Vinegar and Duct Tape Overnight Soak for Limescale

Materials Needed

  • Vinegar
  • Gloves
  • Bucket
  • Rags
  • Duct tape
  • Brush
  • Mirror
Toilet Bowl scrubber brush, holder and gloves
Temples Pride 3 pack Kit

Temples Pride 3 Pack Toilet Bowl Scrubber Brush and Holder with Free Gloves kit can be helpful


  1. Turn of the water supply to your tank from the main supply line to the bathroom area.
  2. Clean out the toilet by flushing it one last time and getting rid of the water in the bowl. This is to give it space and freedom to really get under the toilet rim.
  3. Confirm that there’s no water trickling down the water tank in an attempt to fill up for the next flush.
  4. When the toilet bowl is dry, tape the area under the toilet bowl so that it remains firm on the porcelain under the rim, covering the water jets.
  5. Fill the water tank with vinegar and flush the toilet. This way water will be sealed by the duct tape allowing the rim to soak in the vinegar for as long as the tape is secured there.
  6. After about an hour to overnight, remove the duct tape to release the vinegar, scrub gently and check to see if the dirt is cleared.
  7. Open the waterline and flush again to allow for clean water to run through the jets.

Baking Soda and Vinegar

A mixture of baking soda and vinegar tends to generate a chemical compound called carbonic acid, which is aggressive on stains and mineral deposits on surfaces. It will be an excellent remedy for this problem.


  1. Measure about a cup of vinegar and pour it inside the toilet bowl. Swish it around so it gets to every area in the bowl.
  2. Let it sink in the bowl for about half an hour to one hour.
  3. After that time, open the box of baking soda and sprinkle it all over the toilet. The vinegar you added previously will entire it sticks on the walls of the bowl.
  4. Add some vinegar to activate a fizzy reaction.
  5. Let it fizz for another 15 minutes, then come back and brush the interior surface of the toilet bowl with precision to under the rim.
  6. Scrub the toilet with a soft hand brush and rinse off by flushing. The toilet should be stain free.

Borax and Vinegar

Borax is also great at multipurpose cleaning, especially on really tough stains. A mixture with vinegar only makes it better.


  1. Add about a cup of borax into the toilet bowl.
  2. Add some vinegar right over the borax.
  3. Gently scrub the toilet. Let sit for 15 minutes and flush the look as you scrub again.

Borax Paste

For those really stubborn stains, a borax paste should do the trick. Here’s how you can do that;

Borax cleaner


  1. Wipe down the toilet bowl to get a clear view of where the mold is.
  2. Make a paste in a dish using borax and water. Ensure the paste is thick enough to stick on the walls of the bowl.
  3. Apply the paste over the hard stained areas and scrub gently with the hand brush to make sure the paste all over the bowl.
  4. Leave it on for half an hour.
  5. Once back, scrub again gently to scrape off the brown stains.
  6. Flush the toilet to finish up.

You can replace the water for vinegar or hydrogen peroxide in case you want a more reactive solution. Just ensure you add only a little amount so the borax can still mount on the wall.

What is the Black Stuff/Ring under the Toilet Rim?

As mentioned above, under the toilet rim is the nastiest area that plays home for bacteria, mold, and mildew. The black lining under the rim could be caused by three main elements;

  • Mold – with over 90% likelihood, mold spores look to bred in the darkness. The fungus also likes moist undisturbed areas such as these hence very unlikely for you to see mold or mildew underneath the rim.
  • Bacteria buildup – the most prevalent bacteria found in toilets or generally moist regions such as the washroom is the Serratia Marcescens. It causes pink residue that eventually turns black after a while.
  • Mineral deposits – hard water stains appear as brown, bronze, grey, and black stains which either form rings or settle on the base of the toilet. Appearing under the rim is most likely due to the siphoned jets found there.
How to clean black stuff/ring under toilet rim
Black stuff under rim

To clean the black ring resulting from hard deposits, use vinegar and baking soda and scrubbing brush.
For micro-organisms, mildew or mold use bleach to sanitize and clean. Check the procedures above.

Alternative Cleaners…When Everything Fails

If the above DIY methods fail to work, you can try commercially available cleaners that are specifically formulated to clean toilet bowl stains.

Note that some of these products may end up damaging your toilet…they are not meant for all types of toilet bowl surfaces. Be sure to go through the manufacturer’s instructions before use.


This is a reusable rubbing stone that rids toilets of rust and lime buildup when DIY options and industrial chemicals fail. Pumice cleaning stone is safe on porcelain bowls. Shapes to fit curved or flat surface. Safe for hands. Safe around children and pets.

Pumice can be used to clean toilet bowl

If the stains or black stuff feels like it is permanent, pumice is the way to go. Do not overuse. Only use it once in a while with a lot of care to avoid damage to the bowl surface.

Iron Out Automatic Toilet Bowl Cleaner

This is one of the best rated automatic toilet bowl cleaner for stubborn hardwater stains and heavy iron deposits. Iron out cleaner

Iron out automatic toilet cleaner tablets & Powder
Iron out

It does not only get rid of heavy-duty stains but it is also formulated to prevent rust stains from forming in your bowl for up to 45 days!

All you need is to clean your bowl with the powder or liquid form of this cleaner then insert the tablet in the tank. Iron out is safe for all toilets, plumbing and septic systems

Bio Clean-Eco Friendly Hard Water Stain Remove

If you are looking for an eco-friendly option, Bio Clean Hard Water Stain Remover cream is what should get. It is biodegradable and generally safe for yourself and your home.

Bioclean hard water stains remover
Bio clean

You do not water when using this clean. Straight from the bottle, simply apply directly to the surface with stains.

Use a clean dry cloth to remove the product after you have used the included brushes or brushes of your own. Then, wash or rinse with water.

Clorox ToiletWand Disposable Toilet Cleaning System

Clorox toiletwand toilet bowl cleaning system
Clorox Toiletwand

The Clorox cleaning system comprises of a toilet wand, a storage caddy and original disposable refills plus 10 Rainforest rush scented refills that kill 99.9% of bacteria and viruses in your bowl.

The hexagon shaped sponge heads clean in hard-to-reach places under the bowl rim and drain for a deeper and faster clean to remove rust, calcium and lime stains.

It is an all-in-one bathroom household cleaner. No need for scrubbing brushes and other cleaning items.

Power Drill Brush Scrubber

Another not-so-common way to easily clean underneath your bowl rim like a boss is to use a drill brush.

Bathroom Power Drill Brush
Drill Scrubber

These bathroom cleaning accessories are relatively recent but it will definitely fun to try them out. Check price and reviews

Recurring Stains Under Rim

If the discoloration keeps on appearing in the bowl after cleaning, there’s a good chance it’s mildew growing in the tank.
To find out simply lift the toilet tank lid and check. If you see black deposits, clean it up with vinegar or bleach.

If you want to go a step ahead, that is, to clean not only underneath the rim but also the openings are located here, we’ve done an article on how you can cleanout and unclog the flush holes around the rim of your toilet.

Tips to Keep under the Toilet Bowl Rim Dirt Free

Following are tips to prevent buildup of dirt under the rim and other parts of your toilet.

  • Clean regularly, at least once a week to prevent the accumulation of heavy stains
  • Ensure there’s enough ventilation in your bathroom to avoid dampness.
  • If your toilet bowl is old, damaged, or worn, make a point of replacing it since worn and damaged surfaces make it easier for stains and debris to build up.
  • Another tip from users around the internet is to leave the toilet lid up. Mold is known to develop when there is too much moisture build-up over extended periods. The toilet lid traps sufficient moistures under it and at the same time enough of the same moisture to evaporate from the bowl…

Further Reading

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