Why Is There Pink Mold and Black Slime in My Shower?

Have you ever come across some weird substances growing in your shower? Pink mold and black slime are some repeatedly emerging molds in showers and bathrooms. 

Pink mold and black slime grow in moist surroundings where the temperature is warm enough. The shower is the most suitable place for hosting such microbes as there is complete exposure to humidity and a mild environment. 

Let’s dive deep and learn more about pink mold and black slime so that you can easily identify and treat these microbes in the future. 

What Is Pink Mold?

Pink mould embedded into the shower tile

“Pink mold” is a word used to define the water-borne bacteria “Serratia Marcescens.” This bacteria is commonly known as pink mold because it’s pink in color. However, the color might vary from different shades of orange to red. This bacteria grows well in warm and damp environments. Thus, it is found in bathrooms, especially in the shower and bathtub. 

Molds are natural substances in the outdoor and indoor environment in our daily lives. Although they are naturally occurring and quite commonly present, discovering molds within your house should be taken seriously. 

What Is Black Slime?

black mold in shower tile

Black slime is a term used to define a water-borne mold or fungal spore that grows in an extremely moist environment. They are commonly found in subtropical low climates. The black slime grows in places like on the faucets, in the shower, on the sink, and in the toilet.

Black slime is not the gluey substance that your children play with nowadays. Instead, it is a type of mold that grows in the presence of a moist and damp environment. Black slime doesn’t exist in water, but they grow exponentially when exposed to water bodies. 

Black slime can grow easily in your washroom. Thus, it is necessary to stay mindful and check for such molds within your area, so that you can timely remove them. 

Causes of Pink Mold and Black Slime in Your Shower

Pink mold is caused when the Serratia marcescens and aureobasidium pullulans get a perfect breeding environment in your shower. Then they feed on minerals and chemicals present in the soap residue and other products. While on the other hand, Black slime emerges due to excess iron and manganese bacteria in your water supply. 

After learning about what these two molds are, the next step is to know how they come into existence. Let’s take a brief overview of the cause of each mold. 

Pink Mold

Pink mold is caused when the Serratia Marcescens come together and are exposed to a perfect breeding environment. This microbe grows rapidly once it finds a moist and damp place, along with warm room temperature. Once the microbe starts to grow, it feeds on the minerals present in tap water and chemicals from the soap residue. 

Black Slime

Black slime is caused due to the iron and manganese traces in the water flowing into our washrooms and shower. The bacteria feed on the iron and manganese oxidizing in the water supply. As a result, a black slimy substance grows near the faucets and shower.

How to Identify if Your Shower Has Pink Mold and Black Slime?

As the pink mold emerges because of a pink-red colored microbe, thus look out for red hues on your washroom tiles, shower, and other things in the bathroom. For black slime, look for blackish brown dirt that doesn’t come off even after scrubbing. 

You know what pink mold and black slime are, but an important question is how you can identify if you have either of the molds growing in your shower.

If you notice pink to orange stains in the grout of shower tiles, on the shower curtains, or even on places like the toilet bowl and walls, you can conclude that there is pink mold growing in your shower.

On the contrary, black stains or dirt suggest that the iron and manganese bacteria feed on the minerals in the water supply. These black stains don’t come off easily, even after a good scrub!

Do Pink Mold and Black Slime Carry Any Side Effects?

Pink mold is said to be linked with urinary infections and gastrointestinal problems. It can also contribute to skin infections and other derma problems. While on the other hand, black slime is not very toxic to the human body.

According to multiple pieces of research, pink mold is a mild dangerous substance growing inside your shower and washrooms. Pink mold can cause:

  • Urinary tract infections
  • Wound infections
  • Gastrointestinal problems
  • Lungs infection
  • Rashes all over the body
  • Allergy and other skin problems

However, on the other hand, black slime is considered to be a neutral substance that doesn’t directly damage your physical health. It is a rather non-toxic substance.

Ways to Get Rid of Pink Mold and Black Slime From Your Shower

spray vinegar before clean the black mold

Substances like bleach, liquid dish soap, baking soda, and white vinegar help to wear off pink mold and black slime from faucets, shower walls, curtains, and tiles.

Now that you know how to identify these molds be mindful while inspecting your shower. If you come across either of the two molds growing inside your washroom, you can use the following substances to remove them completely:

  • Bleach
  • White vinegar
  • Lemon juice
  • Baking soda
  • Liquid soap and other chemicals can break down these molds.

Just take a sponge and use either of the mentioned solutions to scrub walls, curtains, tiles, or any other area affected by pink mold and black slime. 

How Can You Prevent Pink Mold and Black Slime From Reappearing?

There are multiple ways through which you can prevent pink mold and black slime from reoccurring. Any activity or practice that helps to reduce moisture and humidity from your shower and washrooms will be useful.

As we now know that these molds grow in our showers due to excess exposure to the wet environment, you can follow these tips to make sure your shower is mold-free:

  • Dry your shower walls and shower curtains after you take a bath. 
  • Wash your shower curtains with warm water to ensure that no mold is growing on them.
  • You can use antimicrobial curtains that are designed to keep the shower mold-free.
  • Use an exhaust fan before and after you take a bath. This will help reduce moisture inside the washroom.


After reading this article, you will have enough information about pink mold and black slime. You can follow the mentioned ways to remove these molds and prevent them from reappearing in your shower.

Leave a Comment