My Hot Tub Smells Like Chemicals (Here’s How to Fix It…)

By Dillon •  Updated: 03/19/21 •  11 min read

My hot tub smells like chemicals.

A hot tub that smells like chemicals is often the result of too many chloramines in the hot tub. To get rid of chloramines, add 30g (1 capful) of oxidizer to the spa. Another reason could be the pH is not balanced correctly. The pH should be between 7.4 and 7.6. Finally, if the spa water has not been drained for a long time, it could produce a foul chemical odor. Draining the hot tub is the best course of action if this is the case.

Check out my list of high-quality hot tub products to help keep your hot tub clean and running great all year long!

My recommended product to help you test your hot tub or pool water for accurate pH, alkalinity, bromine, and chlorine readings is the AquaCheck Trutest Digital Reader.

If you recently purchased a hot tub, this problem might be bothering you. Fortunately, you’re reading this article to understand why your hot tub might smell like chemicals and how you could resolve the issue.

Let’s get started!

My Hot Tub Smells Like Chemicals, Why?

Hot tubs that smell of chemicals are a common complaint that most hot tub users bring across. It’s almost impossible for you to enjoy a therapeutic soaking when your hot tub is choking with bad chemical smells.

Unbalanced pH levels are one of the causes of a bad smell in your hot tub. For low pH levels, your hot tub will produce a pungent odor.

For an extremely high pH, the hot tub will smell stale. The recommended pH for your hot tub water is between 7.4 and 7.6.

Low sanitizer levels can also make your hot tub smell like chemicals. The role of sanitizers is to eliminate bad odors from the hot tub water. When the sanitizers get low, the hot tub water may start smelling like chemicals, begin to foam, and look cloudy.

The hot tub cover might also be the cause of a bad smell in the hot tub water. The trapped moisture in the spa cover forms bacteria that produce a bad smell. Removing the cover and thoroughly cleaning it will resolve this issue.

When you use chlorine and bromine, bad smells can be left in your hot tub. Chlorine or Bromine’s reaction with organic compounds in the hot tub water leaves disinfection by-products in your hot tub. These by-products are noticeable from the heavy chemical scent they produce in the hot tub. The best way to resolve this problem is to shock your hot tub with chlorine or non-chlorine hot tub shock. For more information on hot tub shock, check out our article.

How Do I Get the Chemical Smell Out of My Hot Tub?

To properly remove the chemical smell out of a hot tub, ensure that the hot tub pH is well balanced and adequately sanitized. The pH should be between 7.4 and 7.6. To sanitize, add 30g (1 capful) of oxidizer to the spa. Next, add another 30g of sanitizer (either chlorine or bromine) to the water. Sanitizer levels should be between 1-3 PPM for chlorine or 2-6 PPM for bromine. Let the spa mix and sit for 24 hours and check if the smell disappears.

I have seen that pH levels that fall out of the 7.4 and 7.6 range can make your hot tub smell like chemicals because of scale and biofilm formation. If you diagnose this to be the problem, you can resolve it using a bio-purge product to purge the hot tub.

You should also maintain high sanitizer levels to kill bacteria and eliminate the bad odors. Shocking a hot tub is recommended at a frequency of a few weeks, depending on how heavily the hot tub is used.

Draining the hot tub and refilling it with fresh water is another good solution to the bad smells in a hot tub. The practice helps to prevent the growth of mold in the hot tub. Also, I advise maintaining the chemical balance of the hot tub water to prevent the possibility of bacterial growth. For more information on draining hot tubs, check out our full article on the subject.

Old covers can trap the hot tub water and cause a bad smell. If your hot tub cover is too old, consider its replacement. But if your hot tub cover is still serviceable, ensure to clean and maintain it sufficiently.

You could also address the problem by cleaning and sanitizing the pipes thoroughly. Proper cleaning of the pipes helps to eliminate biofilm build-up. Ensure that you are adding enough sanitizers alongside any pungent treatment to your hot tub.

When emptying the hot tub, add Oh Yuk Cleaner to clean out the hot tub pipes.

How to Get Rid of Chloramines in a Hot Tub

To get rid of chloramines in a hot tub, add 30g (1 capful) of oxidizer to the spa. This oxidizer is also called hot tub shock and comes in two versions, chlorine and non-chlorine. I recommend the chlorine spa shock to remove chloramines from the hot tub. Add this to the hot tub once every week to ensure the spa remains clean.

I want to mention one misconception many hot tub owners have regarding chlorine. Most people think that the strong chlorine smell from a hot tub indicates the hot tub water’s cleanliness. But this is not true!

Chloramines cause a strong chlorine smell in your hot tub. And chloramines are not good because they can irritate your skin or eyes. Indeed, chloramines are an indicator of poor treatment of your hot tub. How can you remedy this problem?

I recommend the use of a shocking agent such as a non-chlorine shock or an oxidizer. Before you do so, make sure to use a test strip to determine the presence of chlorine in your hot tub.

After shocking the hot tub, you should leave it for 30 to 60 minutes so that the shocking agent can remove the bad odors. You can repeat this process until chlorine gets to the correct levels. Shocking the spa should remove any bad odors in the hot tub caused by chloramines.

I recommend SpaGuard Enhanced Shock for a chlorine oxidizer.

How to Get Rid of Bromine Smell in Hot Tub

If excessive amounts of bromine cause odors, you can leave the hot tub for two to three days. After this period, bromine levels will have gone down. The pH should be between 7.4 and 7.6. To sanitize, add 30g (1 capful) of non-chlorine hot tub shock to the spa. Make sure to remove the hot tub cover for a short time for the fresh air to get into the hot tub water.

Besides leaving the hot tub to restore the correct bromine levels, you can neutralize the water manually. This means that you will add more water into the hot tub to mix the excess bromine. Hopefully, this will restore bromine to the desirable levels.

You can also use a neutralizing chemical to lower the bromine levels. For instance, you can add sodium thiosulfate to your hot tub water. You can find neutralizers online.

But I do not encourage adding neutralizers too often because this will increase your hot tub water’s chemical levels. The extra chemicals in your hot tub complicate the process of balancing the hot tub water. It can also affect other hot tub characteristics, including alkalinity, pH, and calcium hardness.

Check out our article on bromine tablets for more information on how to properly sanitize your hot tub.

For non-chlorine hot tub shock, I recommend the Leisure Time Shock Treatment.

I recommend Thio-Time Chlorine and Bromine neutralizer to help balance your spa water.

Should a Hot Tub Smell Like Chlorine?

No, a hot tub should not smell like chlorine. The chemical smell is not expected in a properly treated hot tub. The chlorine smell means unbalanced chlorine levels in your hot tub with the presence of chloramines. If you don’t want these smells to come from your hot tub, ensure that chlorine levels are between 1-3 PPM in the hot tub and shock the spa with chlorine hot tub shock.

You should always test for chloramines and the total chlorine to ensure they are at the right balance. Ordinarily, the total chlorine should not exceed the chloramines. If this happens, shock your hot tub water. After 24 hours, you can retest for the chlorine levels to see if the right balance has been achieved. If so, you will notice that the foul odor will have disappeared.

The chloramines are left after the added chlorine has cleaned the hot tub water. When checking the chlorine levels, I use the test strip to determine chlorine levels. When your hot tub water has ammonia from oils and other organic material in the spa, the chlorine starts reacting.

The test strip will fail to detect any free chlorine in the hot tub water as it gets locked into the battle with ammonia. The combination of chlorine with ammonia forms chloramines. The total chlorine exceeds the free chlorine levels when this happens. The resultant chloramines create a strong chlorine smell in your hot tub.

When you add an oxidizer, the chloramines are broken down to eliminate the smell they cause in the hot tub. I recommend adding sufficient amounts, add 30g (1 capful) of oxidizer to the spa. Additionally, I advise you to run the jets for some time for the shock to mix with the water. After doing so, remember to balance your water chemistry again.

I usually advise people to shower before getting into the hot tub to avoid leaving oils and respirations in the hot tub. These forms of dirt are sources of ammonia that react with free chlorine to create chloramines. Remember that your hot tub should not smell like chlorine.

Check out our article on chlorine tablets for more information on proper chlorine sanitization for your hot tub.

Consider Using a Water Care Monitor

Monitoring the health of your hot tub can often be challenging if you are not testing the water on a regular basis. This can also be a problem if you go on holiday or you are unable to take care of your hot tub due to mobility issues.

The pHin Smart Water Care Monitor for pools, hot tubs, and inflatable spas continuously tests the water and alerts you when to add chemicals with the integrated mobile app.

The mobile app will inform you when to add chemicals such as chlorine, and how much chemical is recommended. This is done by entering your hot tub or pool’s unique dimensions.

Simply scan the bar code of any chemical brand and the pHin app will calculate how much chemical is to be added to the water. Most products and brands are recognized by the application.

The pHin device will sample water more than 1000 times per week to give you an accurate reading compared to using test strips.

The pHin device works with different water types including chlorine, bromine, and saltwater hot tubs, swim spas, inflatable hot tubs, and pools.

This unique device comes with a lifetime warranty to ensure your water remains clear and ready for you to use at all times.

Check out our article on how to fix cloudy hot tub water for more information related to proper water chemistry.

Are Hot Tub Fumes Dangerous?

Yes, hot tub fumes can be dangerous if there’s too much chlorine present in the hot tub. Hot tub fumes are the chlorine vapor that comes from the water surface. When inhaled, one can suffer from health complications such as throat irritation, dry eyes, dry skin, and skin rashes. If the water is properly maintained and balanced, this should not be an issue.

The effects of the hot tub fumes can be problematic for asthmatic people. If the vapers from the spa water are bothering you, the best thing is to remove yourself from the spa and treat the water. If that doesn’t work, drain the spa.

My Hot Tub Smells Like Chemicals: Conclusion

hot tub smells like chemicals

A hot tub that smells like chemicals is often a result of poor chemical balance in the spa water. To resolve the problem, ensuring proper water maintenance remains a top priority.

I hope you found this article on hot tubs smelling like chemicals helpful.

Check out this great article from swimuniversity.com about ways to properly maintain your hot tub.

Thanks for visiting spatoolkit.com

Dillon

I'm Dillon, creator of SpaToolKit.com. During the day I'm a software developer for an engineering company. At night I enjoy sitting in my hot tub and relaxing. My hope is that Spa Tool Kit will be a place where you can find the best information on hot tubs, spa equipment, setups, parts, and accessories. Let's get started!

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