Why Your Hot Tub Smells Like Chemicals (and How to Fix It)

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If you've ever noticed your hot tub smells like chemicals, you're not alone. This is a common problem that can be caused by a variety of factors. In most cases, the problem can be resolved by making a few simple changes to your hot tub maintenance routine.

One of the most common causes of hot tubs smelling like chemicals is not having enough sanitizer present in the water.

In this article, we'll take a look at how to identify the cause of the chemical smell—and what to do about it.

A chemical smell usually means you don't have enough sanitizer

If you notice a strong chemical smell coming from your hot tub, you might think it's because of too many chemicals. But in most cases, it's actually because you don't have enough sanitizer in the water.

Sanitizer helps to keep the water clean and free of bacteria, and it's important to maintain the proper levels in order to keep the tub safe to use.

Why does low sanitizer cause a chemical smell?

If your hot tub smells like chemicals, it's likely due to high levels of chloramines or bromamines.

Chloramines and bromamines are compounds that are formed when your chlorine or bromine reacts with sweat, oils, and other organic matter in the water, and releases into the air.

To get rid of the smell, you'll need to shock the hot tub. This will kill any bacteria and free up your sanitizer so it can get to work again.

Why does my hot tub smell like ammonia?

Chloramines are a compound that is formed when dissolved chlorine reacts with ammonia. This is a normal and expected part of the sanitization process in hot tubs. However, chloramines can also cause a foul odor, similar to the smell of ammonia.

Ammonia can come from sweat, urine, or other sources, so it is important to check the sanitizer levels regularly and shock the hot tub on a regular basis. By taking these precautions, you can help to ensure that your hot tub stays clean and fresh-smelling all year round.

How to fix the chemical odor in your hot tub

If your hot tub smells like chemicals, there are a few things you should do to fix the problem. First, check the water balance, including pH level, total alkalinity, and calcium hardness. If anything is too high or too low, fix these things first.

I have a free printable hot tub maintenance schedule which you can download to remind you of exactly what to do.

The next step is to check the sanitizer level. If the chlorine or bromine is too low, it can cause a chemical odor. You can fix the sanitizer level with a testing kit and either chlorine granules, or bromide (depending on whether your hot tub is sanitized with chlorine or bromine).

If you've checked the pH, TA, and sanitizer levels and they seem fine, the next step is to shock the hot tub. This should kill any bacteria that may be causing the odor. You can buy hot tub shock at most pool supply stores.

If you can't get the water balanced or the smell doesn't seem to go away after shocking, it's probably time to empty the tub and start fresh—especially if the water has been in there a while.

Depending on usage, you should aim to change your hot tub water every 3-6 months.

Be sure to balance and add the correct amount of sanitizer to the new water, and test the levels regularly to ensure that the tub stays clean and safe.

Why is it important to get rid of the chemical smell?

While chloramines and bromamines are a normal byproduct of sanitizer being effective at killing bacteria, they can also be quite irritating to the skin and eyes. In high concentrations, they can also cause respiratory problems.

That's why it's important to make sure your hot tub is well-ventilated, and to shock your hot tub at least weekly to avoid excessive build-up of chloramines or bromamines.

What to do if you are having trouble maintaining correct chemical levels

If you are having trouble maintaining the correct water balance in your hot tub, it is best to contact a professional for help. A professional can test the water and make recommendations for the best chemicals to use and routine to follow. They can also help you troubleshoot any problems you may be having with your hot tub.

Maintaining the correct chemical levels in your hot tub is essential for keeping the water clean and safe to use. So if you are having difficulty, your local pool or spa store will usually be able to offer help or advice.

In summary

If your hot tub smells like chemicals, it's most likely due to a lack of sanitizer.

First, check the water balance, including pH level, total alkalinity, and calcium hardness. Then, check the sanitizer level. Finally, shock the hot tub. If you can't get the water balanced or the smell doesn't seem to go away after shocking the spa, it's probably time to empty the tub and start fresh.

If you follow these steps and the chemical odor persists, you may need to call a hot tub technician for further diagnosis and assistance.

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