Black Mold in Toilet (Causes, Risks & What Should You Do)

Many homeowners don’t realize that their toilet is a prime spot for mold to grow. This is because mold thrives in environments that are dark and wet. The most obvious sign of black mold is when you notice a black ring in the toilet bowl.

Black mold is a risk to homeowners because it can cause people to feel sick all the time, forgetful, and frequently tired. When you notice signs of black mold, you should immediately clean the entire toilet and inside the tank. Experts recommend using a 1:1 bleach and water mixture to clean black mold.

Have you noticed a black ring in your toilet bowl? Don’t panic. Today, we’re going to discuss why black mold is in your toilet and what you should do about it. Read on to find out how you can prevent this problem from taking over your bathroom.

What Is Toilet Mold?

Toilet mold is usually present along the water line in the toilet bowl or right below the rim. This mold starts off as a tiny fungus that produces spores and spreads throughout the toilet.

One thing to know about toilet mold is that it isn’t a specific type of mold. There are various types of mold that can grow within your toilet. However, black mold is the most common type of mold that homeowners will find in their toilets.

You can identify black mold by color. It’s black with a grey or greenish tint to it. Homeowners have also been able to notice mold by a musty smell in their washrooms.

What Does Toilet Mold Look Like?

You should address the issue as soon as you notice black mold growth in your toilet because it can be a health risk to your household. This is why it’s important to understand what black mold looks like.

Black mold typically starts off as small black circles. The mold isn’t always pure black. You may notice other shades in it, such as grey, green, brown, or even orange. It’s common to find a black ring around the water line.

You may notice that it looks like the mold is dripping down when the black mold is growing beneath the rim. This occurs when the mold begins to spread.

Source: Reddit
Source: Reddit

What Are The Risks When Dealing With Black Mold In A Toilet?

Mold exposure can be very dangerous to your health. Children, senior citizens, and people with respiratory issues are at a higher risk. People who are exposed to black mold could feel sick constantly. Some of the signs are a dry cough, sore throat, and nasal congestion.

People that are sensitive to mold may even experience flu-like symptoms. Mold exposure can also cause inflammation in people’s joints and muscles.

Fatigue is another common symptom of mold exposure. This can leave people feeling tired or weak from everyday activities. Some people may even feel drowsy, especially if they have consumed alcohol.

Many homeowners will experience irritated eyes as well. Some signs of this are itchy, watery, and red eyes constantly.

Mold exposure doesn’t just affect people physically. It can also affect them mentally. This can lead people to have trouble remembering things or lose concentration easily.

Is Black Mold In The Toilet Dangerous?

The good news is, black mold in the toilet is easier to clean than in other areas of the house. The bad news is, black mold in the toilet is dangerous to your health. Even though the mold is sitting in the toilet, it can still become airborne. Any time you flush a toilet with black mold in it, particles from the mold can be dispersed into the air.

You don’t have to be exposed to a large amount of mold for it to be dangerous to your health. Even small amounts of exposure can lead to the symptoms we mentioned above. Unfortunately, children and senior citizens are at a much higher risk when mold is present in the bathroom.

That being said, you don’t have to panic if you’ve spotted mold in your toilet. It’s not dangerous if the mold is spotted and dealt with right away. The mold that has developed because you haven’t kept up with cleaning the toilet or appeared along the standing water while you were on vacation isn’t as big of a risk as mold developed from cracks and rusty pipes.

What Causes Black Mold In A Toilet?

The #1 reason black mold is present in a toilet is the moisture. This creates a home in which the mold can thrive in. Mold can easily spread within 1 to 2 days of forming. Many homeowners have noticed it growing in their toilet when they’ve come home from a short vacation.

It’s normal for mold to form if the toilet hasn’t been cleaned in a while. This is especially true if the bathroom has poor ventilation. However, if you’ve recently cleaned and the mold is back within a few days, then there is a bigger problem. Let’s take a look at what it could be.

Hard Water

Hard water is one of the top causes of black mold in a toilet. This happens because hard water leaves mineral deposits. These mineral deposits build up and create a welcoming home for mold and bacteria.

There are a few signs other than black mold that can point to hard water.

  • White residue on your sink and shower faucets
  • Red, brown, or grey stains in the toilet and shower
  • Soap scum builds up easily
  • Dishes look spotty after they come out of the dishwasher

Stagnant Water

Standing water can cause mold to develop. This is why you can come home to find mold in your toilet after a vacation even though you haven’t had issues with mold in the past. Since there isn’t any water flow, it’s easier for the mold to spread.

Another reason mold can spread quickly in your toilet is not flushing. Some homeowners won’t flush after every use to conserve water. You might notice a black ring appear quickly if this is something that gets done in your household.

Moisture And Darkness

Any area that is dark and moist can see mold develop. Bathrooms are known to be more humid than other rooms in the house. Mold is more likely to develop if the bathroom isn’t well-ventilated. It can also develop quickly if you take hot showers or baths without the bathroom fan running.

A lot of homeowners leave their toilet lid down when it’s not in use. This is why they find mold growing quickly in their toilet, but not the bathroom sink or shower. Since moisture and darkness aren’t avoidable, it’s important to clean the toilet regularly.

Rusty Pipes

Do you clean the toilet regularly but still continue to see mold returning within a few days? Black mold in the toilet can come from another part of the toilet’s system, such as the pipes. Rusty pipes are prone to condensation, which can create a home for black mold to start growing and spread to other parts of the toilet.

How quickly the mold returns is one of the signs that the problem could be rusty pipes. This is because you will clean the mold you see, but there’s still a lot of mold that you’re unable to see and clean. When this occurs, the mold will be back within a few days of cleaning.

Cracks In The Toilet

Cracks can develop over time in ceramic toilets. Your toilet may have cracks in it if it’s older. This can happen because the toilet is less efficient after many years of use. It can also occur if the bathroom experiences frequent temperature changes.

When cracks develop, it won’t be long until black mold appears. This is really difficult to clean because the mold can stick inside the fractures of the crack. Homeowners with cracked toilets can clean their toilets on a daily basis, but the mold will continue to flourish. You should replace the toilet if there’s a crack in the bowl because it can lead to further damage.

How Can I Prevent Mold From Growing In My Toilet?

You can prevent mold from growing in your toilet by reducing the amount of moisture in the bathroom. The moisture from the toilet water, showers, and using the sink can affect the air quality in the washroom. This can cause mold to develop along the toilet and in extreme cases, the shower.

Luckily for homeowners, there’s a very easy and efficient way to prevent moisture from causing mold to develop. This is to make sure your bathroom has a working fan. Make sure this fan is turned on when you use the shower, bath, or toilet. Many fans come with a timer so you won’t have to keep them running all day.

Here is one thing to consider. Most homes have a bathroom fan, but yours might not be working properly. To see if it is, turn it on and place a piece of toilet paper near it. The fan is working correctly if the toilet paper sticks to it. If the toilet paper falls t the ground, you will need to replace the fan.

How Can I Remove Mold From My Toilet?

You can remove mold from the toilet by cleaning it. When you do this, it’s important to take your health and safety into consideration. We strongly recommend that you wear rubber gloves and a face mask before attempting to remove mold from the toilet. This will prevent you from breathing in any airborne mold and keep your skin protected from the cleaning product.

Are you wondering how you can use these products to remove mold from your toilet? Read on to find out what you need to do.

Clean The Toilet Bowl and Under The Seat

When you notice mold in your toilet, you will need to clean the bowl and under the seat. These are the most common spots for mold to grow on.

  • What you need: baking soda, disinfectant wipes, a cleaning eraser, toilet bowl cleaner, container to mix ingredients
  1. Put on gloves and a face mask to keep yourself safe.
  2. Inspect the toilet to find where the black mold is spreading from. You will likely notice mold underneath the rim.
  3. Place equal parts baking soda and toilet bowl cleaner in the container. You don’t have to measure the ingredients out. A rough estimate will be sufficient.
  4. Use the cleaning eraser to mix the toilet bowl cleaner and baking soda together until it forms a paste.
  5. Lift the toilet seat so you can clean along the rim. Put a generous amount of the cleaning paste on the cleaning eraser and scrub the rim inside the toilet bowl to remove the mold. You may need to apply pressure to remove it all.
  6. Place some toilet bowl cleaner inside the toilet bowl. Use the toilet brush to clean the rest of the toil. Give extra attention to any areas where mold is forming around the water line.
  7. Flush the toilet and inspect to make sure you have removed all the mold.
  8. Use disinfectant wipes to clean the outside of the toilet and underneath the toilet seat.

Cleaning The Toilet Tank

There’s a good chance that there’s mold in the toilet tank if you found it in the toilet bowl. This is why you should clean the toilet tank after removing mold from the toilet bowl. Citric acid is the most effective product to clean mold from a toilet tank. It can dissolve mold and other forms of buildup with minimal scrubbing.

  • What you need: warm water, citric acid
  1. Put on gloves and a mask to keep yourself protected.
  2. Turn off the water valve going to the toilet.
  3. Flush the toilet to remove the remaining water in the tank.
  4. Pour a bucket of warm water into the tank. Pour the water so it’s just above the mold and buildup. Warm water is needed to loosen up the mold.
  5. Add approximately one cup of citric acid to the toilet. Use something that you don’t mind getting dirty to stir the water. This will help mix the cleaning agent with the water.
  6. Allow the mixture to sit for one hour. After the hour has passed, you can flush the toilet. Most of the mold should be dissolved by then.
  7. Turn the water back on to the toilet.
  8. Flush the toilet one more time to remove leftover mold particles.
  9. If there is any mold remaining after the second flush, use a cleaning brush or old toothbrush to scrub it off.

Natural Solutions To Get Rid Of Mold

Citric acid is an excellent ingredient to use for mold removal. It’s efficient and natural. Many homeowners prefer using this over bleach or mildew and mold cleaning agents that have heavy-duty chemicals. However, citric acid isn’t the only product you can use. Another great natural solution is hydrogen peroxide.

You can pour hydrogen peroxide into a spray bottle and spritz it on the bleach in your toilet bowl. Research has shown that hydrogen peroxide can kill mold, fungi, and other types of bacteria.

There’s one more great natural solution you should know about for mold removal. Rosemary oil has very strong antibacterial properties. You can make an excellent natural mold removal paste using:

  • 1 part baking soda
  • 1 part dish soap
  • Several drops of rosemary oil

Homeowners can use this paste on an old toothbrush to scrub away mold in the toilet.

Other Methods To Remove Mold From A Toilet

There are multiple ways you can remove mold from a toilet. This all comes down to what products you have on hand and what you prefer to use. Let’s take a look at two other ways that you can successfully remove mold from a toilet.

1. EC3 Laundry Additive Method

EC3 is a laundry additive that’s used to remove mold and bacteria that’s on clothing. Homeowners can also use this product to clean black mold from appliances in their homes, such as the toilet. While this product is very strong and does the job, it doesn’t contain any harsh chemicals.

Here is how you can use EC3 to remove black mold in your toilet.

  1. Pour approximately 1/2 cup of EC3 laundry additive into the toilet bowl.
  2. Use a spray bottle to spritz EC3 along the rim of the toilet where mold forms.
  3. Close the lid and let it soak for an hour. If the mold buildup is heavy, you may need to let it sit for longer than an hour.
  4. Use a non-abrasive toilet brush to scrub the toilet and remove all traces of mold.

2. Baking Soda and Vinegar

Most households have baking soda and white vinegar in the pantry. They’re inexpensive and have a lot of uses. What you might not have known is the combination of these 2 ingredients can be used to clean mold from a toilet bowl. Here is how you can use these ingredients to remove mold from a toilet.

  1. Gather baking soda, white vinegar, and a magic eraser or scrubbing pad.
  2. Turn the water off and flush the remaining water from the toilet.
  3. Generously sprinkle baking soda in the toilet bowl and toilet tank.
  4. Pour white vinegar into a spray bottle. Spritz all the baking soda with the vinegar.
  5. Allow the vinegar and baking soda to sit for approximately one minute.
  6. Use the scrubbing pad to remove the mold. Apply pressure as needed to get off any caked-on mold.
  7. Depending on how severe the mold build-up is, you may need to repeat the above steps a few more times. This is to ensure all of the mold has been removed.
  8. Turn the water back on and flush the toilet so the vinegar mixture doesn’t sit around.

When To Call A Professional

You should call a professional if the mold continuously returns. The toilet should be cleaned at least once a week. If you notice signs of mold reappearing between weekly cleanings, then there is a more serious problem. This likely means that there is mold growth in areas that you can’t get to.

The problem may call for you to have the toilet or the pipes replaced. This is a job that should be managed by a professional plumber. You should also contact a professional for any problem causing mold that you can’t fix by cleaning, such as hard water.


Mold in the toilet is something that almost any homeowner could come across. To reduce your chance of black mold growth in the toilet, you should keep the bathroom well-ventilated. Good quality air and airflow are essential for preventing mold.

Keeping your toilet clean is also important for keeping black mold away. This doesn’t just include the toilet bowl. You will also need to make sure the toilet tank, under the seat, and around the toilet is kept clean. The best product to use to clean mold from a toilet tank is citric acid. For mold in the toilet bowl, you should use a paste made from baking soda to remove it.

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