What Causes Pink Stains on Toilets and Bathtubs?

Renovating your bathroom lavishly, making it look exceptional and aesthetic, only to discover stains on your toilets and bathtubs; ugh! I understand how aggravating that is. It ruins your entire effort as well as the appearance of your bathroom. Here’s why pink stains happen on toilets and bathtubs:

If you have noticed pink stains on toilets and bathtubs or even sinks in your bathroom, one of the main reasons for their occurrence is bacteria that are a common inhabitant of our environment. And the most common type of bacteria is Serratia marcescens.

Even if it is not harmful, you should still be taking care of it.

In this article, I will be uncovering one of the most pressing plumbing mysteries and will discuss the causes of the occurrence of pink stains and what you can do to remove and avoid them.

What Are the Pink Stains on Toilet Bowl?

The pink stains on the toilet bowl can be a mold (the most common suspect), rust or it could even be colored dye. Most people complain about these stains in the summer months. The good thing is that not every pink mark is dangerous, and there is no need to worry about it.

Here is what different suspects can mean:


When you see a pink stain in your bathroom, your first suspect is probably a pink mold because it is the most common thing to appear. 

This pink mold, also known as Serratia Marcescens, is caused by bacteria. The bacteria causes unsanitary colonies in your bathroom and may pose a few health hazards. (Discussed in more detail further in the article)

If you notice pink molds in the toilet bowls, you should be worrying about it. The bacteria colonies in toilets can cause urinary tract infections. 

You can determine whether the pink stain is because of the bacteria; by its hue and texture and bindingness with the porcelain. Serratia Marcescens have bright pink to orange-like tone and a slimy pink texture. 

pink toilet stain
Image from Deanna Weedmark Hennessy


Another typical stain that your pink stain could be is rust. 

Although rust has a deep orange-red hue, it can turn pink after some time. Hence, the best advice is to get it fixed immediately. They can cause painful wounds on the skin; when bumped against the rough surface of rust.

It can also lead to expensive repairs if the rust is in your pipes, as they can cause structural damage.

Colored Dye

There is also a possibility that you may be stressing out for no reason. And the pink stain that you see is possibly a colored dye. 

It is common for your hair color to come out when you wash it. Sometimes, rather than going down the drain with the water, the colored dye stays. It then leaves a stain in the bathtub.

What Is Serratia Marcescens?

Serratia Marcescens is an airborne bacteria that thrives on moisture you will find in everything, so it is not unusual if it appears in your bathroom. The Serratia bacteria seek out and grow in moist and dusty conditions and have a pinkish-red pigment.

Serratia Marcescens

The main components a Serratia bacteria needs to survive are water, air, and phosphates that your shampoos, shower gels, and other bathroom products have. Making the bathroom the best place for Serratia marcescens to thrive.

While the problems posed by Serratia marcescens in the form of pink stains are less in quantity and are not even harmful, they can still cause infections and pneumonia, so let us look at how they appear and what you can do to get rid of them.

It feeds off the residue of soap or shampoo.

How Do Pink Stains Appear?

When we talk about pink stains, we’re referring to the bacteria Serratia Marcescens, as previously stated. Now before I tell you how you can remove the marks, it is crucial to know what causes the bacteria to appear in the first place.

pink stains in the bathroom
Image from Pro Clean Solutions Saddleworth

The bacteria feeds through organic material in your bathroom, such as soap scum. Besides that- it grows tremendously in moist and humid areas. 

So you will find the pink stains more in summer. Once the marks start to turn red in pigment, it is a sign for you to consider solving the issue because that means the bacteria has grown in size.

If you see pink stains in your bathtub, it is because the bathtubs are moist and filthy and have organic matter. And the same can happen with your shower walls.

Or, if you see the stains on your toilet or sink, the reason is the water that stands long enough for the residual chlorine disinfectant to dissipate. The bacteria, however, do not survive in chlorinated water.

There is also a possibility that you notice pink stains on shower curtains, mainly if your curtain consists of natural fibers like cotton or wool.

How to Get Rid of Pink Stains in Toilets?

To get rid of the pink stains, first, you will have to get rid of the bacteria that causes it. You will have to start cleaning your bathroom regularly and thoroughly. It is best to clean it with chlorine disinfectant because the bacteria can not survive then.

cleaning toilet water jets

Below are some of the methods you can follow for cleaning the stains:

  • One of the most effective methods is to make a one-part vinegar and one-part water spray. Spray the mixture and scrub with a soft-bristle brush. 
  • For more set-in stains, you can use chlorine bleach in the bathtub, sink, and toilet.
  • To clean the shower curtains, put them in the laundry with a cup of baking soda and white distilled vinegar.

However, if the pink stains you notice are rust, you will have to find a plumber or maintenance service to get the job done for you by removing and repairing the rusted areas.

Similarly, if it is a colored dye, use a bleaching solution such as hydrogen peroxide to remove the stains. However, while you do so, be careful! Letting the bleach sit in for a long time can worsen the mark rather than fix it.

How to Keep Pink Stains in Toilets From Reappearing?

If you did not already know, the pink stains reappear even after you have followed the methods mentioned above to remove them. 

Yes, you heard it right! Here are a few steps to stop them from reappearing and having your bathroom shine again!

vinegar and baking soda in two bottles
  • When cleaning your bathroom, ensure that you do not scratch a fixture or surface, as the bacterial growth will likely rise.
  • Get in the habit of drying your sinks and bathtub after every use with a rag or squeegee to prevent standing water.
  • Turn on the ventilation fan to keep the air circulation running, and open a couple of windows to decrease humidity.
  • Clean your toilet often to prevent the bacterial colonies from taking over.
  • Never clean your toilet with a bathtub scrubber or soft-bristle brush since these tools can scratch the surface and may be responsible for some of the stains.
  • Using vinegar, water, and baking soda to disinfect all surfaces in your bathroom is another great way to stop the pink staining marks from reappearing on your bathroom fixtures again.


Now that you’ve learned everything there is to know about the pink stains in your bathroom- it is time to put your worries to rest.

Start following the steps to remove and avoid the pink stains; it is not even hard. And get the aesthetics of your stunning bathroom back!

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