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How to Effectively Get Rid of Hot Tub Slime

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Dealing with hot tub slime isn’t just frustrating; it can harm your health. The presence of slime affects the aesthetic appeal of your hot tub and poses potential health risks. Understanding the causes of slime in your hot tub and implementing effective strategies to eliminate it is essential for an enjoyable hot tub experience.

In this guide, we will discuss the various factors contributing to hot tub slime and provide information on how to get rid of the sticky substance effectively to ensure safe and relaxing spa water.

What Is Hot Tub Slime?

how to get rid of the sticky substance

Hot tub slime, often called biofilm, is a sticky layer of microorganisms that forms underwater on hot tub surfaces. It’s a complex mixture of bacteria, algae, and other organic matter that adheres to the hot tub’s walls, filters, and plumbing. This biofilm creates a slimy feeling and provides a breeding ground for harmful bacteria.

What Does Hot Tub Slime Look Like?

Hot tub slime typically appears as a greenish, brownish, or grayish slimy layer on the hot tub’s surfaces. It can cover the walls, floor, and even the waterline. The slime may have a slippery texture and can feel unpleasant. In some extreme cases, it might look like patches or streaks of discolored or cloudy water. If left untreated, the slime can become more pronounced and affect the water quality.

Effective Methods to Get Rid of Hot Tub Slime

Hot tub slime can be a frustrating and unsightly problem for hot tub owners. Fortunately, there are many ways to get rid of it.

Shock Treatment

Shock treatment is one of the most effective ways to eliminate hot tub slime. Shock treatments involve adding a large amount of sanitizer to your hot tub, which can kill off bacteria or other contaminants. This can help break up and get rid of biofilm accumulated in your hot tub.

To shock your hot tub, you should first test the water to ensure that the water’s pH level and alkalinity levels are within the recommended range. Then, according to the manufacturer’s instructions, add the appropriate amount of shock treatment to your hot tub. Be sure to run your hot tub’s jets for at least 30 minutes after adding the shock treatment to help distribute it evenly throughout the water.

Use of Enzyme-Based Cleaners

Another effective method for eliminating biofilm slime is using enzyme-based cleaners instead of chemical cleaners. Enzyme-based cleaners contain natural enzymes that can break down and digest organic matter, including biofilm. These cleaners are often gentler on your hot tub’s surfaces than harsher chemical cleaners, making them a good choice for regular maintenance.

To use an enzyme-based cleaner, add the appropriate amount to your hot tub according to the manufacturer’s instructions. Be sure to run your hot tub’s jets for at least 30 minutes after adding the cleaner to help distribute it evenly throughout the water. Using an enzyme-based cleaner prevents you from using too many chemicals and protects the hot tub’s lifespan.

Deep Cleaning

Deep cleaning of a slimy hot tub is essential to restore its cleanliness. Drain the tub and scrub surfaces, plumbing, and jets with a hot tub cleaner and soft brush. Be sure to rinse all cleaners thoroughly.

Causes of the Slimy Buildup in a Hot Tub

Slimy water buildup in a hot tub can be frustrating and unsanitary. Understanding the causes of this buildup can help prevent hot tub biofilm from happening in the first place. 

Here are some common reasons why hot tubs become slimy:

Poor Water Chemistry

Poor water chemistry is one of the most common causes of slimy buildup in a hot tub. If the pH balance is off, it can create an environment that allows bacteria and other microorganisms to grow. 

Similarly, if the sanitizer level in a hot tub or spa with water is too low, it can allow bacteria to thrive. Regularly testing the water and adjusting the chemicals as needed is the key to maintaining the proper balance.

Infrequent Cleaning

Another cause of slimy buildup in a hot tub is infrequent cleaning. Over time, dead skin cells, skin oils, and other contaminants can accumulate in the water and the tub’s surfaces. 

If you don’t regularly clean the hot tub’s plumbing, this buildup can create a breeding ground for bacteria and other microorganisms. 

Most manufacturers recommend cleaning the hot tub at least once a week and draining/refilling the water every 3-4 months.

Bacterial Growth

Bacterial biofilm growth is a frequent culprit behind the slimy substance buildup in hot tubs. Bacteria can infiltrate the tub from various sources like swimmers, pets, or the environment. 

Imbalanced water chemistry can lead to rapid bacterial multiplication, resulting in a slimy film on the hot tub walls and surfaces. Maintaining proper water chemistry and regular tub cleaning is crucial to prevent bacterial growth. 

Using a spa purge product can further aid in eradicating existing biofilm and preventing future accumulation.

Tips to Prevent Hot Tubs From Becoming Slimy

Keeping the water surface in your hot tub clean and free of slime is essential to ensure a safe and enjoyable experience. Here are some tips to prevent the water’s surface in hot tubs from becoming slimy:

Regular Cleaning

Regular cleaning is critical to prevent the buildup of bacteria and other microorganisms in your hot tub’s filter. 

Make sure to keep your filter clean by cleaning your hot tub’s filters at least once a week and replacing them every three to six months. 

You should also drain and clean your hot tub every three to four months to remove any biofilm buildup.

Proper Chemical Balance

Ensuring the proper chemical balance in your hot tub prevents slime buildup. Test the water regularly using a test strip or a digital tester to ensure the various pH levels, alkalinity, and sanitizer levels are within the recommended range. Also, follow the manufacturer’s instructions for adding chemicals to your hot tub.

Proper Sanitization

Sanitizing your hot tub is essential to kill bacteria and other microorganisms that can cause slime buildup. Chlorine or bromine are the most used sanitizers used in hot tubs. 

Make sure to add the recommended amount of sanitizer to your hot tub regularly and shock your hot tub after heavy use.

Shower Before Soaking

Encourage everyone who uses the hot tub to shower before soaking. This will help remove any dirt, sweat, body oils, or other contaminants contributing to slime buildup in your hot tub.

Cover Your Hot Tub When Not in Use

Covering your hot tub when not in use is essential to prevent debris from getting into the water. This will help to reduce the amount of bacteria and other microorganisms that can cause slime buildup. Make sure to use a high-quality cover that fits your hot tub properly and is in good condition.

These tips can help prevent slime buildup in your hot tub and ensure a clean and safe soaking experience.

Maintaining a Slime-Free Hot Tub

Hot Tub Slime

Hot tubs provide a therapeutic experience but can also be a breeding ground for mineral buildup, slime, and bacteria. Regular care is essential to keep a hot tub clean and slime-free.

Here are some tips on how to maintain a slime-free hot tub:

Regular Inspections

Regular inspections ensure the hot tub is in good condition and slime-free. The following are some areas you should have inspected regularly:

  • Filter: The filtration system should be inspected and cleaned regularly to ensure it works properly. A dirty filter can cause ineffective water circulation, which can cause slime to build up in the hot tub.
  • Pipes and Jets: The pipes and jets should be inspected regularly to ensure they are free of slime and debris. Remove any buildup immediately to prevent further growth.
  • Cover: The cover should be inspected for any tears or damage that can allow dirt and debris to enter the hot tub.

Use of Quality Water

The water quality in the hot tub can also affect the growth of slime and bacteria in fresh water. Here are some tips to ensure that the hot tub water is of good quality:

  • Regular Water Testing: Regular water testing is essential to ensure the water is balanced and contaminant-free. Also, check the pH and alkalinity levels regularly.
  • Use of Quality Water: Quality water is essential to prevent slime and bacteria growth. Hard water can create scale buildup, which can lead to slime growth. The use of soft water can help prevent this issue.
  • Water Replacement: Regularly replace the water in the hot tub to prevent contaminant buildup. How often you should replace the water depends on how many people use the hot tub and how frequently.

By following these tips, hot tub owners can maintain a slime-free hot tub and ensure a clean and relaxing experience.


What Are the Signs of Biofilm in a Hot Tub?

Biofilm in a hot tub can be identified by the presence of white or grayish slime on visible exterior and interior surfaces, the water’s surface, the hot tub’s walls, or the plumbing. The water may also have a foul odor and appear cloudy.

What Is the Best Hot Tub Cleaner for Removing Slime?

Several hot tub cleaners effectively remove slime and biofilm from hot tub filters, including spa purge products and enzyme-based cleaners. Choosing a cleaner created for hot tubs and following the manufacturer’s instructions is essential.

Is Biofilm in a Hot Tub Dangerous?

Biofilm in a hot tub can create the perfect environment for harmful bacteria and other microorganisms to grow. This can put the well-being of hot tub users at risk. Regular cleaning and maintenance are essential to prevent the formation of algae growth of biofilm in a moist environment and ensure the safety of users.

Can Vinegar Effectively Kill Biofilm in a Hot Tub?

While vinegar may have some cleaning properties, it is ineffective in killing biofilm in a hot tub. Using a hot tub cleaner specifically designed to break down and remove biofilm from slippery water is important.

Is It Safe to Use a Hot Tub With Slime Present?

It’s best not to use a hot tub with slime present, as it can expose you to harmful bacteria and other microorganisms. It is important to drain and clean the hot tub thoroughly to remove any slime or biofilm before using it again.


Knowing how to eliminate hot tub slime is crucial for a safe and enjoyable hot tub experience. Regular maintenance, proper water chemistry, and preventive measures like enzyme-based cleaners and shock treatments can help prevent and eliminate slime in a hot tub.

By consistently following these steps, you can say goodbye to slime in your hot tub and welcome a relaxing hot tub environment. Your dedication to upkeep will ensure your hot tub remains a sanctuary of comfort and enjoyment.