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Toilet Mold – What It Is, How To Remove It, and How To Prevent It

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Have you ever lifted the lid of your toilet only to be greeted by a ring of black mold? Or maybe you “gotta go” while visiting a friend but hesitate to get down to business after noticing pink toilet mold just under the rim of the bowl.

Although it is an unwelcome site, toilet mold is ridiculously common. The good news is that it is easy to remove and very preventable. 

What Is Toilet Mold?

Just like all mold, toilet mold is a fungus that thrives in a warm, moist, dark environment. It isn’t necessarily one specific type of mold. There are various molds that can take up residence in your toilet.

What Color Is Toilet Mold?

Mold comes in a lot of colors. Black toilet mold is the most common color that forms a “ring” in your toilet. This ring can also be from green mold or grey mold. Orange or pinkish slimy mold can develop around the toilet bowl at the spot where the top of the water sits in the bowl.

What Causes Toilet Mold?

Since bathrooms tend to have higher humidity levels it is easy for airborne mold spores to take root in a toilet bowl since it is often left open.

Stagnant water is a great environment for mold. Toilets that are used infrequently and not flushed often are more likely to develop a mold problem than those that are flushed many times a day.

If your toilet tank has mold growth, then it is passing those mold spores into your toilet bowl. You can have a moldy toilet bowl without a moldy toilet tank however.

Why Is Mold Growing In The Toilet Bowl Only?

  • Organic surfaces such as the tank’s walls and hard water deposits help supply mold with a nutrient source.
  • What you put in the toilet can increase the likelihood of mold growth. The PH of urine and body chemicals found in your poop can all effect whether or not a toilet bowl grows mold. In fact, there is a really interesting diabetes and mold connection. Mold LOVES sugar. It is one of it’s preferred foods. When a person has diabetes that is uncontrolled or not adequately controlled, the body reacts to its decreased ability to process glucose by essentially “dumping” it via urine and sweat. That glucose-rich fluid serves as food for mold spores inside the toilet bowl.
  • You could have black mold in the water supply from the pipes or tank. If this is the case the mold will re-establish itself every time you flush the toilet. Rust on the pipes can also cause condensation which leads to black mold. 
  • There could be cracks in the ceramic of your toilet. These cracks give black mold a place to stick, grow and flourish.

Why Is Mold Growing In The Toilet Tank Only?

Toilet tank with mold

Typically mold that is growing in the toilet tank and not the bowl is due to infrequent use. It gets quite warm in a toilet tank which sets up a breeding ground for mold. In addition, the chlorination that helps kill mold will go down due to the toilet not being flushed.

If you find mold underneath the toilet tank it’s because you have a worn-out washer. The current washer isn’t effectively sealing and the water is slowly dripping out and running along the bottom of the tank. Replace the washer as soon as possible by doing it yourself or call a plumber.

Is A Ring In The Toilet The Same Thing As Mold In The Toilet?

Not always! A red rust or brown colored ring forms from calcium and magnesium mineral deposits that come from your water. If you scrub the inside of your toilet and can’t get it clean, then it’s a hard water stain and not mold. The mineral deposits have etched their way into the porcelain making it near impossible to remove.

If you want more information about toilet bowl rings (including nicotine rings), this toilet bowl ring post is pretty awesome.

Is Toilet Mold Dangerous?

It can be especially if it appears within a day or two of you cleaning your toilet. This usually means that you have a larger mold issue in your home.

Just like any mold, toilet mold can lead to a wide variety of health issues especially in those people who are allergic to mold or already dealing with other health issues.

Ways To Remove Toilet Mold

Because toilets are made of glazed porcelain, removing mold from them is usually pretty easy. A word of caution – NEVER use bleach to clean mold. Please read that post if you are considering a bleach cleaner in your toilet. Also, never use a pumice stone to scrub the inside of your toilet. This damages the porcelain.

Since mold can be hazardous to your health, you want to make sure that you are wearing a mask, eye protection, and gloves before using one of these methods to remove mold from the toilet bowl or tank.

Cleaning Mold From The Toilet Bowl

I am sharing not only the best way to remove mold from your toilet bowl (and the one I use) but also a few other options should you prefer to try one of those first.

Before you begin, start by closing the water supply line. Locate the shutoff on the wall behind the toilet and twist the valve completely clockwise to close. Then flush the toilet and drain out as much water from the bowl and tank as possible.

The Best Way To Remove Mold From The Toilet Bowl

Steam clean it! Yes, you read that right! Bust out your handheld steam cleaner and steam the mold right out of your toilet. This is the handheld steam cleaner I have used for years! Hasn’t failed me once.

PurSteam Handheld Portable Steam Cleaner
$47.97
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10/16/2023 07:13 pm GMT

Here’s how to do it.

  1. Place the angle nozzle attachment on the hose of your steam cleaner. This is the steam cleaner I use.
  2. Steam the toilet bowl and underneath the rim at high pressure to loosen the stains.
  3. Direct more steam on the hinges and the toilet seat edges to loosen rust on screws.
  4. Using the stream setting on a spray bottle filled with vinegar OR Superstratum Everyday Cleaner wash off the loosened dirt into the toilet bowl.
  5. Flush the toilet.
  6. If you still see mold, repeat this process a second time.
  7. When all the toilet mold is removed, wipe off any remaining drops of water or steam with a microfiber cloth.

Yep – it is just that easy!

Steam c;leaning toilet bowl to remove toilet mold

Other Effective Ways To Remove Mold From The Toilet Bowl

Superstratum Everyday Cleaner Method

Superstratum Everyday Cleaner is made by applying a low electrical charge to a combination of salt and water. The combination of these ingredients creates Hypochlorous Acid (HOCl). HOCl is all-natural mold and mildew cleaner spray that does not contain any carcinogens or harmful synthetic chemicals, and it’s a lab-tested solution proven to destroy mycotoxins on building materials.

  1. Fill a small spray bottle with Superstratum.
  2. Pour 1/2 cup of Superstratum into the toilet.
  3. Spray the Superstratum under the rim.
  4. Let it sit in the toilet for an hour or more with the lid closed.
  5. After an hour, scrub the mold with a toilet brush or similar non-abrasive material. You want to move the water around the bowl and brush really well under the rim.
  6. Let the toilet sit again for about 15 minutes with the lid closed.
  7. Flush the toilet.
  8. Still see some mold? Scrub any remaining mold stains with a toilet brush or similar non-abrasive material.
  9. Still see some mold? Repeat this entire process a second time.
  10. After you are mold free, let the toilet sit with the lid closed for 3-5 hours before using it again.

To learn why I love the Superstratum product line so much as well as HOW it works to kill both mold and mycotoxins, check out this detailed post about Superstratum.

Superstratum Everyday Cleaner

The Superstratum Everyday Cleaner is White Blood Cell Technology, made by applying a low electrical charge to a combination of salt and water. The combination of these ingredients creates Hypochlorous Acid (HOCl). HOCl is all-natural. Spray the Everyday Cleaner onto mold or fog it into the air to break the molecular bond of microbes and mycotoxins.

Learn More or Buy Now

EC3 Laundry Additive Method

Laundry additive in a toilet? Sounds weird I know. You could use EC3 mold solution concentrate. That works just as well. But I like the laundry additive because it is meant to withstand agitation in the washing machine as well as a high volume of water.

  1. Fill a small spray bottle with EC3 laundry additive.
  2. Pour 1/2 cup of EC3 laundry additive into the toilet.
  3. Spray the EC3 under the rim.
  4. Let the laundry additive sit in the toilet for an hour or more with the lid closed.
  5. After an hour, scrub the mold with a toilet brush or similar non-abrasive material. You want to move the water around the bowl and brush really well under the rim.
  6. Let the toilet sit again for about 15 minutes with the lid closed.
  7. Flush the toilet.
  8. Still see some mold? Scrub any remaining mold stains with a toilet brush or similar non-abrasive material.
  9. Still see some mold? Repeat this entire process a second time.
  10. After you are mold free, let the toilet sit with the lid closed for 3-5 hours before using it again.

To learn why I love the EC3 product line so much as well as HOW it works to kill both mold and mycotoxins, check out this detailed post about EC3.

EC3 Laundry Additive

Add EC3 Laundry Additive to every rinse cycle or directly to the wash basin to rinse away mold spores, bacteria, and foul/musty odors from clothes, towels, and your washing machine.

Learn More or Buy Now
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Vinegar and Baking Soda Method

  1. Pour 1 cup of vinegar into the toilet. This is the vinegar I use.
  2. Sprinkle baking soda around the inside of the bowl and into the vinegar water in the bowl. Be sure to get some up under the rim.
  3. Sit back and watch the volcano of fizz erupt!
  4. Let the vinegar/baking soda sit in the toilet for an hour or more with the lid closed.
  5. After an hour, scrub the mold with a toilet brush or similar non-abrasive material. You want to move the vinegar water around the bowl and brush really well under the rim.
  6. Let the toilet sit again for about 15 minutes with the lid closed.
  7. Flush the toilet.
  8. Still see some mold? Scrub any remaining mold stains with a toilet brush or similar non-abrasive material.
  9. Still see some mold? Repeat this entire process a second time.
  10. After you are mold free, let the toilet sit with the lid closed for 3-5 hours before using it again.

Cleaning Mold From The Toilet Tank

Since the water in a toilet tank can serve as an emergency drinking water supply, I am very careful with what I use to clean a toilet tank.

  1. Pour distilled white vinegar into the tank (with water in it) and allow it to sit for about 3 hours.
  2. Flush the toilet a few times.
  3. If you still see mold, you will need to turn off the supply valve and drain the toilet tank. Then use a toilet brush or similar non-abrasive material and scrub the remaining mold spots.
  4. Turn the water back on and flush the toilet twice.
  5. Add another cup of vinegar to the toilet tank and let sit for 60 minutes.
  6. Flush the toilet twice and you should be mold free!

Avoid using bleach in the tank as it is corrosive to some parts. If the problem persists, use a brush to scrub at the black mold when the water is down after flushing. Repeat until it is clean.

After-Care

After you have removed mold from your toilet bowl and/or tank, be sure to wipe down the entire toilet with Superstratum Everyday Cleaner, EC3 or vinegar. It is also advisable to burn the EC3 Candle for 3 hours.

Do You Need More Toilet Mold Cleaning Power?

I get it. We all don’t have the same amount of elbow grease to give (or maybe you just don’t want to). If you need a toilet brush that basically does all the work for you, I highly recommend the Eletalker Electric Spin Scrubber. This sucker packs a punch and really get mold out of the toilet bowl and tank.

Eletalker Electric Spin Scrubber
$49.99
Learn More or Buy Now
We earn a commission if you click this link and make a purchase at no additional cost to you.
10/16/2023 07:19 pm GMT

How Do You Prevent Mold From Growing In The Toilet?

  • If you have a bathroom window, open it during showering.
  • Make sure that you are using your exhaust fans when you take a shower or bath and leaving them on for at least 30 minutes after you finish.
  • If your bathroom is prone to higher humidity, grab one of these recommended bathroom dehumidifiers and use it during and for an hour after you shower or take a bath.
  • Never leave waste sitting in the toilet. I know a lot of people like to follow the “if it’s yellow let it mellow” motto but when it comes to mold you always want to flush.
  • Clean your toilet bowl once or twice weekly using a scrub brush and Superstratum or EC3.
  • Add 1 cup of vinegar to the toilet tank a few times a week to help prevent the mold.
  • For toilets that are not used often, be sure to flush them every other day.
  • Fix any bathroom leaks immediately.

Remember, no mold is the best mold so make sure that you are taking care to prevent it and remove it correctly if you do find some.

In this post I refer to Superstratum products. They are one of the only two mold and mycotoxins removal products that I personally use and recommend. Please read my article out the Superstratum product line for more information how how they work and the products available. This product lines has never failed me and is great for chemically sensitive individuals. I encourage you to purchase Superstratum products directly through the company website.

In this post I refer to EC3 products. They are one of the only three mold and mycotoxin removal products that I personally use and recommend. Please read my article outlining what makes EC3 superior when it comes to killing mold and mycotoxins. It has been independently lab tested and proven to be 99% effective when used properly. I encourage you to purchase EC3 products directly through Micro Balance. If you prefer to shop on Amazon, Micro Balance has a presence there as well.

A moldy toilet tank with the caption "toilet mold - what it means and how to remove it" written below

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40 Comments

  1. I have an ongoing debate about whether to keep the lid up or not. I think it actually creates more mold under the rim. (I’ve noticed the difference..ie more mold when lid melt down) My son in law also thinks stuff goes outside if you don’t put the lid down. To me it gets on the inner lid if you do. Help judge this debate!

    1. Hi Barbara! What a fun debate! HA! If you leave the lid up and flush “stuff” does fly a decent distance out of the toilet. Kind of gross. If you put the lid down it has no choice but to spray the rim. So yes, more mold growth. Leaving the lid down also creates a bit more humidity in the bowl which can allow more toilet bowl mold to grow. The best of both worlds is to flush with the lid down and then open it back up after it is done. This allows air flow and will let the lid dry out. Hope this helps!

  2. Hi Jennifer,

    Thank you for your article.
    We get black mold in toilet within 2-3 days after having cleaned it. You mentioned in your article that this could mean a bigger problem. I have been smelling mold coming out of our master bathroom for about the last 2 to 3 years and I have health problems. Convincing my husband of my issues being connected to mold is a tough one. I do not see the mold anywhere except inside the toilet but the wall of odor is stifling most especially in the winter. Our bathroom is connected to our master so we inhale all of those floors every night as we sleep. I just noticed yesterday when the air conditioner came on that within the hour I had a very sore throat and felt terrible. So, we may have mold in our air ducts and who knows where else.
    Neither of us are in great health so we may have to hire out and are a bit terrified about what money may have to come out of pocket. Nonetheless, can you please give me suggestions as to how to proceed. Thank you so much!

    1. Hi Mindy! You absolutely want to run an ERMI test in your home. https://moldhelpforyou.com/ermi-test/ This post gives you all the information you need to order the kit and do it yourself. You can email me the results and I can interpret them for you. I am so sorry for the delay in responding! Please let me know if you have other questions or need help figuring out how to do the ERMI test. It is super simple though and that post walks you through the basics.

  3. Jessica-Jean says:

    So, does this mean that all the usual toilet cleaners found in supermarkets (Lysol, etc.) are useless?

    1. Hi there! Anything that is bleach based is going to be bad news. Some of the enzyme based cleaners are ok to use. Honestly, once your toilet is clean, keep it that way by just using a toilet brush and a little vinegar 2-3 times per week. The only time I would suggest something stronger is if you have had someone with a virus or bacteria in the family that has been glued to the toilet if you get my drift. Then you need to do some sanitation.

      1. Jimmy Luper Jr. says:

        what about mold at the end of my kitchen faucet where the water is disspensed

        1. Hi Jimmy! I would suggest you replace the faucet. That could be happening because of an issue inside your pipes and if that is the case this won’t offer a long term solution. But if it is simply a kitchen faucet issue, then a new one should solve the problem. I do suggest that the end of faucets be cleaned weekly with vinegar. Takes just a couple of minutes to give it a wipe. This helps prevent loads of issues.

  4. bobbie weston says:

    Hi,
    We moved into this apartment in April. In may it was discovered that the pipes in the kitchen were corroded and that there was mold underneath the cabinets. Repairmen came, replaced all the pipes in the kitchen, took out the cabinets and cleaned all the mold. Less than 2 weeks later I discovered a black mold growing in the toilet tank that hadn’t been there when the plumbers did the repairs. We bought the mold test kits and the EC3 kit. During this time what I had thought was a stain at the bottom of the toilet bowl itself revealed itself to be the beginning of a pile of slime that started spreading into the bowl from the little hole at the front of the bowl. Using a scrub brush would move some of it around a little bit but to actually clean any part of it I ended up needing to use a pumice scrubber on it. Unfortunately the scrubber will not fit into the little hole and it just keeps spreading out into the toilet again after about a week. I do not know what kind of slime this is but I am immunocompromised and am allergic to mold.

    Do you have any ideas?

    1. Would you be able to email me a photo of it? This could partly be biofilm. I would really need to see a photo to know for sure.

  5. Hello, we moved into our house several months ago and shortly after realized every toilet in our house has mold in it. We’ve tried several different techniques all for the mold to continue to return. I am considering at this point just replacing all of the toilets. Do you think this would solve the issue?

    1. Hi Korissa! If you are dealing with recurring mold, new toilets are probably in order. If after replacing the toilets and being diligent about cleaning them to prevent mold you are STILL getting mold growth, you may need to look at a possible mold situation within your bathrooms or home. Have you done any mold testing to date?

      1. I have a newly constructed home with a brand new toilet. I find the toilet gets moldy within two days after cleaning it. I had my last house for 40 years and never had that problem. I feel like something is wrong but I don’t know what it could be.

        1. Does anyone in your home have diabetes that was diagnosed since moving in? Is the toilet a low flow or regular flow toilet?

  6. We have a septic system. Are the processes and products for cleaning the toilet okay to use? Thanks.

    1. Yes, provided your septic system is well maintained. There isn’t anything that will back up your system in this protocol.

  7. Your article was helpful, thanks! I mainly have a toilet ‘bowl’ issue of mold appearing in the water and did the vinegar and baking soda tonight. I’ll observe my toilet over the next few days. I have a question – I noticed when cleaning the larger hole that it felt a bit ruff .. my guess from what I could also slightly see is maybe rust ‘bits’? More to my story/Q below*
    You mentioned above … –You could have black mold in the water supply from the pipes or tank. If this is the case the mold will re-establish itself every time you flush the toilet. Rust on the pipes can also cause condensation which leads to black mold.
    *to confirm, that could include a rusty nut or washer in the ‘tank’? I’ll see how my bowl looks over the days, but guessing maybe ask my landlord to change some tank parts. Would it help to send you a photo of my tank? Thank you.

    1. Hi Melanie! Yes, please email me a photo. For as many toilets as I have seen you would be surprised how different they can be. Ha!

  8. Hi, there! We have recently been told a lot about using Benefect Deacon 30 to clean our toilet bowl mold. Then could use the product to clean the bathroom surfaces with microfiber cloths to kill and remove and spores and mycotoxins that could potentially have spread. What are your thoughts on this product and it’s effectiveness?

    1. I have an article on my site about the Benefect product line. You can definitely use this. It doesn’t tackle mycotoxins like some of the other products but that is less of a concern IN a toilet bowl. It would also be fine to use to clean the surfaces as well.

    1. Thanks for letting me know! Yes, this one should do just fine!

  9. Alice Carroll says:

    Thanks for the tip about how using exhaust fans will help in preventing toilet mold. I’m interested in buying toilet drops soon because it’s a bit tricky to fix the air quality in my bathroom. I’d like to try out every product that I could use in order to figure out the right stuff to use.

  10. What if you use the toilet within 3-5 hours of cleaning with baking soda and vinegar ? Is it bad? I added vinegar in the tank as well as baking soda and Vinegar in the toilet bowl

    1. It is totally fine to use the toilet if needed.

  11. Leslie Vergara says:

    Hi Jennifer,

    I diligently cleaned my bathroom under rim with a toothbrush, Branch Basics, and EC3. I have very hard water so it was impossible to remove 100% of the mold. I say I removed about 95%. Any recommendations for the hard water?

    Also, regarding the steamer, would the steam just pick up the mold and set it all over the surfaces of the bathroom? Thank you.

    1. We have very hard water here and I have to use one of those pumice stone scrubbers in the toilet. Have you tried one of those?

      No, the steamer will not do that if used properly.

  12. Mary E Cooper says:

    I have mold in my toilet tank. I seem to be getting bit from something. The mold?

    1. Bit while sitting on the toilet? Sorry for the personal question but are you flushing while you are still sitting on the toilet?

  13. Good Afternoon Jennifer, thank you for your thoughtful and thorough posts! In your experience, can mold ever take on a perfumy smell? My situation is-I seemed to have develop multiple chemical sensitivities (MCS) due to high VOC exposure last year. I had to move 3 times within 9 months and as a result have been hyper vigilant to what I am smelling and/or breathing in. That being said, I moved into my current place last month and immediately noticed a perfumy odor which I initially equated to maybe a carpet cleaner but I think I can rule that out. It seems to be in the front bedroom and bathroom, but not in the back bedroom or bath. The smell only dissipated once after a deep clean but came back less than 24 hours later. Other important things to note: I found mold in both toilet tanks (at opposite ends of the apartment); there was mold or mildew inside the window of the problematic bedroom and there are frequent dripping noises behind the walls. I inquired about the dripping noises and management stated it seems to be community wide, that they had it checked out and were told it is just pipes expanding. Thank you in advance!

    1. *I forgot to also mention, I am having allergy type symptoms most likely from the apartment and per my doctor have ruled out seasonal allergies. My eyes have been getting puffy and I was told it looked inflamed and could be environmental.

    2. Hi Liz! So depending on the types of pipes, yes, they can make little noises as they expand and contract. Usually it is more of a tapping type sound. A full on dripping sound usually is something else. The best place to start would be for a plumber to come in with a thermal imager to see what is going on behind the walls.

      Mold itself typically has that musty type odor. It is the mycotoxins they produce that can be just about anything. My mycotoxins smelled like burnt grease. I have been in homes where it smelled like urine, fresh paint, gasoline, etc… I have heard people say they smelled a sticky perfume type odor. So yes, this can absolutely be a mold/mycotoxin situation. Are you wanting to try to continue living here? If so, I would suggest some DIY mold testing just to get a sense of what might be going on.

      1. Good Afternoon Jennifer, thank you very much for your response! I apologize for my delay-I somehow did not see the response when I checked back earlier this month. That is really helpful to know about the mycotoxins taking on different odors and I will definitely heed your advice about the plumber doing the thermal testing. Yes, I want to try and stay if possible. Since my last post:
        -Maintenance tried changing the dryer hose but that did not rectify the perfume odor and said they could not determine where it was coming from. They also told me that what I was seeing in the tanks was not mold, but rather from the water. This does not seem accurate and I have pictures of it.
        -I have since purchased some DIY mold kits and the EC3 candles you recommend on your post. The mold kit said 5-7 days, so I should be able to unwrap the foil this Saturday. I also recently purchased one of the moisture meters.
        -I informed management about my symptoms and that if there is nothing else they can do, I will be getting a mold and/or IAQ inspection. I have also been getting high VOC, PM and CO2 reads on my indoor air monitor
        Thank you, again! I will post back an update in case it’s helpful

        1. Hi Liz! Great to hear back! Yes, please to post with an update. Maintenance workers are notoriously under educated about mold. 😉

  14. Lynda Meng says:

    I have had mold in one of my 3 bathrooms for a few months now!! I would clean it and it will grow right back!! Not a ring of mold but the whole bowl under the water level. In reading your article just now there can be 2 reasons for it! I became a diabetic recently and my daughter will talk long, steamy showers. IS IT POSSIBLE FOR ALL WATER IN THE HOUSE TO BE BAD?? Except for a kitchen sink and refrigerator, both with filters… no one wants to use or drink the water. Family is afraid that the mold may be in the main line. After reading your article here (just now) I am inclined to believe it’s just the toilet!!! Your article was well written and extremely informative… yet good and simple, straight forward instructions!! An absolute SALUTE to the writer!! Please get back with me in re: to the problem being local to the one toilet or could we be exposed throughout our home… in showers, laundry etc. This has kept me up at nights. Googling this and contacting you here is during the night. I contacted our city water company but they seemed like I was speaking a foreign language!
    Thank you for everything. Is there a phone number I can contact you with? If you can text also, please send me one too. I see them quicker. (8one6)-686-9zero9zero. Blessings-

    1. Hi Lynda! So sorry that I am just seeing this now. This absolutely sounds like a localized issue to the toilet and not a whole house issue. If your family is worried about it being throughout the house, you can test the water yourself. Here is a link to that article: https://moldhelpforyou.com/water-mold/

  15. So I have 12 townhomes in a row all hooked up to the same waterline I only have two toilets in the same house that is collecting mold in my toilets. The rest of my units don’t have any issues I’ve cleaned it with bleach and vinegar and it still comes back every three or four days. What would you recommend? I just put a dehumidifier in the house as well and it’s only showing 50 to 55% humidity.

    1. Interesting. Well it has nothing to do with the water obviously. And there are no mold issues in the bathroom otherwise? Just the toilets?

  16. Mold Warrior says:

    Toilet mold mystery. We have a terrible mold smell emerging from our toilet. Completely overwhelming. There is no visible mold in the bowl, which is cleaned meticulously, even up around the inlet jets under the rim. Additionally there is also no visible mold in the tank either. But both the bowl and the tank wreak of mold.

    We notice the smell becomes worse when the city increases the amount of chlorine in the water supply. Chlorine just seems to make the mold angry and increases the off gassing.

    There is no visible mold in the bathroom and the house is kept at 45% humidity by using a dehumidifier. The smell only comes from the inside of the toilet tank or bowl.

    If a cleaning solution is poured into the overflow valve inside the tank like vinegar or hydrogen peroxide then dark fluid will drain out of the jets (small holes) underneath the toilet bowl rim. Could mold be trapped in the chamber between the tank and the bowl? Like from a toilet back up where waste material got inside the toilet rim holes and contaminated the dark chamber? If so, how can one effectively clean and sterilize that part of the toilet to eliminate the smell? Or are we misunderstanding what is happening? If you have encountered this unique issue please share the best remediation proceedure. Thank you and happy holidays!

    1. Hello! So sorry for the delay in replying. I was in the middle of a huge move and offline. Interesting situation you have. In theory this certainly could have happened. I am assuming you have a two piece toilet? Tank and bowl? Honestly, I would replace the toilet at this point. I feel like this is a situation where there isn’t a great way to get it clean let alone totally “remediated.”