Signs of Mold Growth In Toilets
It can be off putting to lift the lid of the toilet and spot unsightly black rings or worse lurking deep within.
You might be in a public toilet, at a friend’s house or perhaps in a café, bar or other social establishment. You might begin to wonder if you really need to go after all and whether you can just put it off, I mean, that thing looks like a health hazard, right?
But what does it mean when it happens to your own toilet at home? And how did it get there?
In this guide we will examine exactly how mold gets into a toilet and what steps to take to treat it and prevent it from coming back.
Common Signs of Toilet Mold
Bathrooms are usually damp, humid environments which provide the perfect conditions for funguses such as mold and mildew to grow. Spores become airborne and can then fly off land on any surface, including getting inside your toilet or water tank.
Mold especially loves water, especially stagnant water so any leaks, drips or defects can lead to even more prolific mold growth. Bathrooms can be mold heaven!
There are many varieties of mold that are commonly found in bathrooms, with a variety of colours and textures. One of the most common is black slime mold (Stachybotrys Chartarum) which tends to be the kind that is often found in toilets.
You may notice the following signs that mold and mildew have taken hold in or around your toilet;
- A grey, green, black or dark coloured rim under the rim of the bowl – the colour may change over time although the most common colour is black. The texture might be hairy, flat or bumpy
- A ring around the water line – this may be an orange or pink colour. Note; If it is more brown in tone, this may also be caused by mineral deposits in the water supply. If this is the case, it will be difficult to remove or clean as the porcelain will be stained inside
- A pungent, pongy or musty smell
- Dark spots, slime or black stains inside the toilet bowl or the tank that holds the water
Luckily, mold in a toilet is usually fairly easy to treat and prevent so read on to find out more.
Most Common Causes of Mold in Toilet
In most cases, bathroom mold is be caused by stagnant water, excess humidity, poor ventilation, damp problems or leaks. In toilets the most common reason for mold growth is infrequent usage which gives time to problems to develop.
By identifying where the mold problem originates from, you will be able to successfully treat it.
Luckily, mold in toilets is usually pretty easy to remove and treat.
Check below for the common places where you may find signs of mold growth both in and around your toilet.
If it’s Growing Only in the Toilet Bowl
Mold growing only in the toilet bowl itself may be caused by any of the following;
- Infrequent cleaning or insufficient cleaning
- Leaving waste in the toilet – this can ‘feed’ the mold
- Infested water supply – the mold could be coming from the pipes, a water tank or elsewhere in the supply. It could also be caused by rust in the system. This may make it much harder to eradicate unless it is treated at source
- There are some suggestions that mold in the toilet bowl may indicate potential dietary or health issues such as diabetes. This is because mold thrives on sugar so its presence in your toilet may suggest high sugar content in your urine. If you suspect this is the case, you should see you Doctor or Health Practitioner for a check-up.
- Infrequent usage – this leads to stagnant water which mold loves, particularly in hard water areas with high content of minerals
If it’s Growing In the Toilet Tank
Mold which is growing in the toilet water tank may be due to the following causes;
- Infrequent flushing – if the toilet in question is not used very often this can lead to mold or mildew. The water turns stagnant and mold spores enter and feed on nutrients and algae which tend to be present in the water supply. Also, the stagnant water will gradually lose the effectiveness of the chlorine which helps prevent mold formation and the temperature may warm to room temperature, making it even more attractive for mold to make a home.
- Contaminated water supply – see above.
- Infrequent cleaning – most people do not think to clean here often, if ever, and so there may be mineral deposits on the sides which can gather and feed any mold spores that manage to get in. It is also dark which mold loves.
Mold in Toilet Bowl Below Water Line
You may also have defects in the surface porcelain such as cracks which can harbour mold growth and provide a place for it to settle in and flourish. Black spots or coloured rings may also be coming from mineral deposits in your water supply. If it is mold, the good news is that you should be able to clean it off fairly easily so follow the steps below in the first instance.
This type of mold may also be caused by a broken water seal so best to get a plumber to check and repair this or the mold will simply return.
Mold Around, Behind or Underneath Tank or Toilet Bowl
You may spot black slime underneath the tank. This is usually caused by a worn-out washer that allows drips from the tank which run down underneath and cause mold. You will need to replace the washer before treating the mold in this case.
Mold may be growing under the toilet bowl, behind it or anywhere there is excessive damp or leaks.
It may also come from behind the baseboard or toilet partition walls which may not be clearly visible. You may need to take a peek behind the boards to examine the extent of the problem.
In any case, the presence of mold indicates a damp problem or that moisture is somehow getting in. Any leaky pipes, windows or defective bathroom fixtures and fittings can lead to mold formation if not repaired promptly.
Bathrooms tend to offer mold the perfect place to set up home – moist, dark and lovely and warm. Leaks, pools of water, damp areas and drips can therefore all lead to the growth of mold so be vigilant.
Is Mold Growing in the Toilet Dangerous?
Whenever you find mold growing in your home it is best to remove it immediately as it is a potential health hazard and also spreads quickly to new places.
Limited exposure to small amounts is not dangerous for most people, however those with allergies, weak or compromised immune systems or those who are very vulnerable may become seriously ill after mold exposure.
This can cause allergies, respiratory problems, sore throat, runny nose, coughs, sinus congestion, headaches or asthma.
If you become unwell after exposure to mold, see your GP or Health Practitioner.
How to Clean & Get Rid of Mold from Toilet
In this section, we will examine how to deep clean and treat your toilet to leave it sparkling clean and hygienic to use.
Before attempting to clean your toilet, it may be a good idea to turn off the water supply. There should be a shut-off valve located on the wall, turn this clockwise to close the supply.
Also, prepare further by opening all windows and ventilating the room and wearing rubber gloves, eye protection and a respiratory mask.
When you are finished, dispose of all cleaning materials used as they may contain spores which you could spread around your home.
In Toilet Bowl
Toilets are typically made of glazed porcelain so it is not usually too difficult to remove mold.
First, flush the toilet and then empty out all of the water from the toilet bowl.
Sprinkle baking soda generously all around the toilet bowl. Take a spray bottle filled with white vinegar and spray it all around and onto the baking soda you have added. This will cause fizzing to occur. Close the lid and leave for one hour.
Take an old toothbrush, nailbrush or a small scrubbing brush and scrub away the mold, swirling around well to get all areas clean.
Flush the toilet to rinse. Repeat as necessary. You may wish to add a cup of bleach and leave for one hour. However, be aware that bleach can be corrosive so use with caution.
You can also buy special cleaning products that remove mold and do not require any scrubbing but always read the label for directions and follow any safety instructions.
Method 2 – Use a Handheld Steamer
Flush and empty out the water from the toilet bowl as described above. Take your steamer and use the nozzle attachment at high pressure to attack the mold and remove it.
You can also take this opportunity to do the toilet seat, hinges and anywhere else that needs a blast of steam as this will disinfect and kill any bacteria that is lurking.
Flush the toilet. Use a spray bottle with white vinegar to rinse and then dry with a cloth.
Repeat as required.
In Toilet Tank
Pour a cup of white vinegar into the tank water and leave for two hours. Flush a few times. This may be enough to remove the mold.
If mold persists, turn off the water supply and empty out the tank. Spray the tank sides and bottom all over with white vinegar. Leave for one hour. Take a small brush and scrub gently to remove the mold (be careful not to bump any of the parts or dislodge them).
Turn the water back on and refill the tank. Now, flush and check the tank again for any signs of mold.
Repeat as necessary.
Wipe down the whole area with mild detergent. Make a thick paste with baking soda and white vinegar and then apply the paste generously over the mold. Make sure to push it into any crevices.
Leave to sit for half an hour.
Scrub the mold gently with a small brush until gone. Use a damp cloth to wipe down or spray with clean water from a spray bottle then wipe as much as you can to dry.
Repeat as required.
Walls Behind Toilet, Baseboard and Area Around Toilet
Use your vinegar spray bottle on any surfaces you can see, allow to sit for 15 minutes and then scrub with your toothbrush, scrubbing brush or a rag before rinsing and wiping dry.
On Seat or Under Toilet Rim
To get under the toilet rim, make a paste as described above and use a small brush or old toothbrush to apply the paste up and under the rim.
Leave for one hour. Take the brush and scrub away at the mold until it is gone. Rinse with a spray bottle filled with water.
Repeat as required.
You can use a steam cleaner to clean your toilet seat or use a spray bottle of white vinegar. Spray it on and leave for 15 minutes then wipe away with a cloth.
Repeat as required. Dry with a dry cloth.
Preventing Mold On your Toilet
To prevent mold from returning to your toilet after your have cleaned it, follow these steps;
- Keep your bathroom well ventilated, especially when bathing or showering by opening windows or using ventilators or extractors
- Always flush waste away and keep your toilet clean
- Fix and repair any leaks or drips promptly
- Clean your bathroom regularly and use anti-fungal sprays and cleaning products or white vinegar
- Add a cup of white vinegar once a week to your tank to keep mold away. You can also buy special preventative tablets that are added to the tank to prevent mold
- Flush any unused toilets regularly (aim for every few days)
Is Mold in your Toilet a Sign of Diabetes?
It has not been scientifically proven that mold in the toilet is a sign of diabetes however it is often suggested that there might be a link. A study conducted by Doug A. Kaufman did actually find a connection between toilet mold and diabetes.
He concluded that this is because mold is so attracted to sugar and therefore the presence of mold may indicate high levels of glucose in the urine which the body has failed to break down. This can be the case when people are either untreated or under-treated for their condition.
If you have mold and either suspect or know you have diabetes, you should see your GP, Doctor or Health Physician to discuss your health further.
What if the Mold in your Toilet Keeps Coming Back after Trying Everything?
If your toilet is clean, but you notice black stuff reappears soon after flushing, the mold may be coming from the pipes or somewhere else in the water supply.
If you have carried out all recommended cleaning and treatments and the problem still persists you may need to call in a plumber to fix any leaks and identify the source of the problem.