Why Does My Hot Tub Smell Like Chlorine? 


Is your hot tub starting to smell like chlorine? Here is why.

Your hot tub smells like chlorine because you have chloramines in the water. Chloramines or combined chlorine are released into the water due to the unbalanced reaction between the chlorine sanitizer and the contaminants in the water.

The smell that you identify as chlorine is not chlorine. The strong offensive odor that you perceive coming out from your hot tub is the smell of chloramines in the water.

So should a hot tub smell like chlorine? And how do you get rid of the chlorine smell in your hot tub? The answers to all these questions will be revealed below. So let’s get on with it.

Should a Hot Tub Smell Like Chlorine?

A hot tub should not smell like chlorine unless the water is filthy. Your hot tub will only smell like chlorine if the hot tub water isn’t properly treated.

When the water in your hot tub isn’t properly treated, then it is bound to smell when you add chlorine to the water. Hot tub water that isn’t properly treated will have a build-up of hot tub scum.

So when you add chlorine sanitizer to the water, the chlorine combines with the contaminants rather than gets rid of them. This is because the chlorine level is too low to get rid of all the contaminants in the water.

The result of this is the chlorine you added to the water will become used up pretty quickly and that means you wouldn’t have any active chlorine in the water.

Instead, you will have a build-up of chlorine that has combined with the contaminants to form chloramines or used up chlorine. It is the used up chlorine that causes your hot tub to produce that strong offensive smell.

So if you think of it, your hot tub shouldn’t smell like chlorine unless it is not properly treated.

Why Does Hot Tub Smell Like Chlorine?

The main reason a hot tub smells like chlorine is because you have chloramines in your hot tub. Another reason is unbalanced water chemistry, you will need to balance the water chemistry, including pH levels. Free chlorine could also be the case.

If you have low or high free chlorine, you need to use an oxidizer or shock to get rid of it. You just have to be careful with the amount of shock you use. That’s because if you used too much shock (or you accidentally spilled it), then that could be the cause of the chlorine smell.

But, the number one reason for chlorine smell is because of chloramines in your hot tub. Chloramines are produced when chlorine gets mixed with nitrogen compounds. Nitrogen compounds are produced by sweat, urine, fertilizer.  You will have to drain and re-fill the hot tub to get rid of the nitrogen compounds.

Having bad filters can in-directly cause chlorine smell. If the water isn’t circulating enough and you have too much chlorine, then the hot tub liner (made of PVC) will start to smell like chlorine.

So, even if you balance the water chemistry, the hot tub liner will still smell like chlorine. You need to drain, clean the shell of the hot tub, and re-fill to get rid of the chlorine smell.

Last but not least, your hot tub could be smelling like chlorine if you added too much chlorine (tablets). If that’s the case, then you need to remove some chlorinated water and add some fresh water to balance the levels.

Related Read: How To Lower Chlorine Levels in a Hot Tub?

How to Get Rid of Chlorine Smell in a Hot Tub

Here are the steps you need to take to get rid of chlorine smell:

  • Test The Water
  • Adjust the pH Levels in the Water
  • Turn on the Jets and the Circulation Pump
  • Shock the Hot Tub
  • Vacate the Hot Tub
  • Test the Water Again

1. Test the Water

1. Test the Water

The first thing to do is to test the water in the hot tub. You can use a water testing kit, hot tub test strips, or a digital tester to test the water. You should test for the pH levels in your hot tub. Though chloramines in the water are the main reason behind the chlorine smell, your hot tub can also smell if the pH level is off balance.

The ideal pH level for a hot tub is between 7.2 and 7.8 on the pH scale. If your hot tub’s pH level is not within this range, then you need to adjust it before adding chlorine to the hot tub. How do you do that? You’ll find out in just a sec.

The next thing to test for is the chlorine levels in your hot tub. Ensure to test for the free or active chlorine in the water. The ideal active chlorine level in your hot tub water should be between 1ppm and 3ppm.

Since the hot tub smells, the active chlorine level will surely be below 1ppm. This means you need to raise the level of free chlorine in the water. But first, let’s check out how to adjust the pH levels in case it is off in your hot tub.

2. Adjust the pH Levels in the Water

2. Adjust the pH Levels in the Water

If the pH level is off-balance, you will have to adjust it before adding chlorine to the water. This is because adding chlorine to the water when the pH level is off can negatively affect the water chemistry and cause damages to the hot tub.

If the pH level is below 7.2 on the test strip, then you should add a pH up or pH increaser to the water. If the pH level is above 7.8 on the test strip, then you need to add pH down or pH decreaser to the water. Once the pH level is between 7.2 and 7.8, you can go ahead to super-chlorinate the hot tub to get rid of the chlorine smell.

Related Read: 6 Things You Can Use To Adjust Your pH

3. Turn on the Jets and the Circulation Pump

3. Turn on the Jets and the Circulation Pump

You should turn on your hot tub jets and the pump before adding more chlorine to the water. This will ensure that the water keeps circulating so when you add the chlorine, it will be absorbed properly by the water. If you don’t turn on the jets and the pump, the chlorine or shock you add will be concentrated in some parts of the water.

So turn on the jets and the pump to ensure water circulation.

4. Shock the Hot Tub

4. Shock the Hot Tub

You can use chlorine or non-chlorine shock in the hot tub. However, it’s usually best to use chlorine shock when you want to get rid of the smell of chloramines in the water.

There would be instructions indicated on the container of the hot tub shock you purchased. Ensure to follow the instructions when adding the content to the water. To get rid of the smell of chloramines in the water, it is advised to raise the chlorine level above 5 ppm (parts per million). In severe cases where there is no free chlorine in the water, you can raise the chlorine levels to about 10 ppm (parts per million).

You may think these levels are high because the ideal chlorine level for a hot tub to have is between 1ppm and 3ppm. This is true. Your hot tub shouldn’t have more than 3ppm but this is for when you are just adding chlorine to the water.

To get rid of the chlorine smell, you need to add a very high amount of chlorine to the water to get rid of the chloramines and still leave enough in the hot tub to sanitize the water. This is why you should raise the chlorine levels way above 3 ppm.

5. Vacate the Hot Tub

5. Vacate the Hot Tub

You shouldn’t use the hot tub after adding shock to the water. You should leave the hot tub unused for at least 24 hours after shocking. This will give the shock enough time to get rid of the chloramines and offensive smell in the water.

6. Test the Water Again

6. Test the Water Again

After 30 minutes, use your test strips to test the water in the hot tub again. The pH level of the water should be between the recommended range and the active chlorine should also be between 1ppm and 3ppm.

When you test the water, you should test for the level of combined chlorine in the water. The level of combined chlorine should be zero. If the test strips show the there is still combined chlorine or chloramines in the water after shocking, then you need to shock the water again. You should check the manufacturer’s instructions to know how long you have to wait after shocking the water before adding shock again.

When the pH level is between 7.2 and 7.8 on the pH scale and the active chlorine level is between 1ppm and 3ppm, you can use the hot tub again. You will also notice that the water is clearer and the offensive odor isn’t present after shocking the water.

Related Read: Get Rid of Ammonia Hot Tub Smell

How Long Does It Take for Chlorine to Evaporate From a Hot Tub?

It takes between 2 days and a week for chlorine to be evaporated from a hot tub. There is no fixed time frame for chlorine to be evaporated from the hot tub water. The amount of time it takes depends on your bathing habit and the number of people that use the hot tub.

When you add chlorine to the water, the chlorine will completely evaporate when it has been used up. The time it takes to be used up depends on the level of contaminants in the water.

If your hot tub is used by you alone daily, then the amount of contaminants in the water wouldn’t be much since it’s just one batter. This means that the chlorine that you add to the water can remain active for over a week before it evaporates. However, if the hot tub is being used by multiple bathers daily, the chlorine will not last more than 3 days before it is evaporated.

The time it takes for chlorine to evaporate is different from the time you have to wait after adding chlorine to the water before you can use it.

Related Read: Why Are My Chlorine Levels Low?

How Long After Adding Chlorine to the Hot Tub Can You Use It?

When you add the regular dose of chlorine sanitizer to the water, it would take between 30 minutes and 2 hours before you can use the hot tub again. But when you shock the hot tub water by adding a high dose of chlorine, you might have to wait 24 hours or more before you can use the hot tub.

To know how long you have to wait, check the manufacturer’s instructions. If the time frame isn’t indicated by the manufacturer, you don’t need to panic.

Just use your test strip to test the chlorine levels in the water every 30 minutes after adding the chlorine. When the chlorine level is within the recommended range, then you can use the hot tub.

Related Read: How Soon Can You Use a Hot Tub After Adding Chemicals?

No More Chlorine Smell!

Overall, when your hot tub starts to smell like chlorine, the main culprit is usually a high level of chloramines in the water.

But there could be other factors influencing this such as low pH level or low sanitizer level. You should use your hot tub test strips to find out what is causing the problem and then get rid of the smell by shocking the water.

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