How To Lower Chlorine or Bromine Levels In Hot Tub

Chlorine or bromine is an indispensable chemical to keep your hot tub water sanitized. But adding too much sanitizer especially, chlorine or bromine, will increase chlorine levels in your hot tub. And you know that too much chlorine can cause itchy skin or skin irritation. 

In worst cases, chlorine poisoning will occur- responsible for sudden nausea, throat burning, and red skin. Furthermore, for a longer period of time, Your hot tub surface may degrade over time. To overcome these issues, you must reduce the chlorine levels. Now, you may ask- how to lower chlorine or Bromine in the hot tub?

Well, hydroxide peroxide or chlorine/bromine neutralizer is the most effective chemical you can apply to lower the chlorine levels. Besides, we also included other alternative ways to reduce high chlorine levels. So, continue to read to learn about them. 

Is It Safe To Go In A Hot Tub With High Chlorine or Bromine

Too much chlorine level in a hot tub can be problematic. But it will not be an emergency case unless the chlorine level starts climbing above the safe range. So, it will be better if you check the chlorine level frequently. 

The high chlorine level can only cause skin and eye irritation. However, it depends on how high the chlorine level is and how you react. Indeed, too much chlorine level is not life-threatening.

safe levels of chlorine or bromine in hot tub

But the problem is- inhaling too much chlorine can be problematic and lead to chlorine poisoning. Itchiness, mild chest pain, red skin, and burning throat are some symptoms of chlorine poisoning. 

High chlorine levels can corrode the metal parts of your hot tub. So, test the chlorine level frequently and keep the hot tub water balanced. 

How To Lower Chlorine In A Hot Tub? 

hot tub chemical test kit

Lowering the levels of chlorine or bromine in your hot tub will be a piece of cake if you know how to do it. And the following 6 alternative ways will work like a charm to reduce the bromine or chlorine levels in your hot tub. 

Leave Your Hot Tub 

We all know too much chlorine or bromine in your hot tub will cause itchiness and rash. And fortunately, you don’t need to do anything to reduce or lower the chlorine or bromine level in your hot tub. Yes, you heard the right words. 

What you need to do is- just leave your hot tub and stop yourself from adding extra doses of bromine or chlorine until it gets the sanitizer level below the optimal parameter. In other words, the high level of chlorine will dissipate naturally.

Also, make sure you pull the chlorinator or chlorine floater out of your hot tub. 

Leave The Cover Off

From above, you learned chlorine or bromine levels will decrease naturally. But if you notice the chlorine is still high after leaving the hot tub for a day or two, it’s time to open your hot tub. 

Afterward, remove the cover from it and let your hot tub get sun exposure. UV rays of the sun will break down the chlorine or bromine. Besides evaporating the chlorine level, sun exposure also decreases the water level. 

So, we recommend you add fresh water to your hot tub. We hope it will lower the chlorine level of your spa. 

Try Out Hydrogen Peroxide To Lower Chlorine In Hot Tub

Hydrogen Peroxide is an effective chemical agent to reduce chlorine levels. Now, you may ask- how much hydrogen peroxide is to lower chlorine in the hot tub?

Well, it depends on how much water your hot tub can hold. Generally, we recommend you add 2 ounces of it per 100 gallons to reduce chlorine or bromine level by 10 ppm. 

However, don’t forget to check out the application process written on the package. 

Apply Ascorbic Acid

Ascorbic acid or vitamin C is also an effective ingredient to lower the chlorine level of your hot tub. Keep in mind; a bottle of grocery store chewable vitamin C tablets will do nothing. You need to get the commercial ascorbic acid that is intended to reduce chlorine levels. This commercial agent will help you burn off the extra bromine or chlorine level in your hot tub. Just apply the right doses of ascorbic acid in your hot tub following package instructions. 

Give the Neutralizer A Shot

A neutralizer will help you lower the chlorine or bromine level in your hot tub right off the bat. You don’t need to wait a day or two to soak yourself in your hot tub. 

Chlorine neutralizer products like sodium thiosulfate will be best to reduce chlorine levels. For your 100 gallons hot tub, you should add 1 oz of this chemical ingredient to lower bromine or chlorine levels. 

Maintain the application guide written on the package and apply the neutralizer in your hot tub gradually. 

Dilute Your Hot Tub Water

Diluting your hot tub water is another alternative way to reduce the high chlorine level. If any methods we mentioned above don’t work, try this technique out. 

In this case, take a bucket and start draining your hot tub water. We recommend you remove as much as half the water to reduce chlorine levels quickly. 

Then, add fresh water to dissipate the chlorine level. You can also turn the jets on to let them circulate your hot tub water. 

Furthermore, a properly balance chlorine or bromine distribution is important. You should choose reliable floating chlorine or bromine dispenser for your hot tub.

Hot Tub Chlorine Maintenance Guide 

If you want to maintain your hot tub every week, do the following things. Make sure you remove the hot tub cover and keep the pump running. 

  • Start with cleaning your hot tub filter. Use a hosepipe to suck away any debris or dirt and leave the filter to dry. 
  • Then, use a test strip to check the pH and alkalinity level of the hot tub. Make sure the pH level is between 7.2-7.6. If the pH level is getting low or higher than the recommended level, you can use a pH increaser or decreaser to adjust it.
  • Now, check the chlorine level of your hot tub and ensure it’s between 3-5 mg per liter. You can add chlorine granules if the level goes down. 
  • If you use your hot tub heavily, you must shock your hot tub once a week. It will keep your hot tub water clean

How To Lower Combined Chlorine In Hot Tub

Shocking your hot tub with chlorine is the best way to reduce or lower the combined chlorine in your hot tub. However, if you have combined chlorine in the hot tub after shocking, understand you fail to reach the breaking point. 

When shocking your hot tub, you must cover off your hot tub and keep the spa exposed to sunlight. Both of these are indispensable to break down combined chlorine. 

Also, you should raise the free chlorine level when you shock the hot tub. We recommend you increase the free chlorine level to 25 ppm. Don’t forget to cover off your hot tub and keep it uncovered for the entire night and day. 

And lastly, keep the pump on when you shock your hot tub to circulate the water optimally. We hope these methods will help to kill the combined chlorine. 

Commonly Asked Questions

How much chlorine to add to a hot tub for the first time?

You can add 60g of chlorine granules per 1500 liters of water to start sanitizing your hot tub. Generally, you need to add high doses of sanitizer to sanitize your hot tub water. Don’t soak yourself in the hot tub unless the chlorine level drops to 3-5 mg. 

How long does it take to lower chlorine in a hot tub?

It may take you 24-48 hours if you want to dissipate the high chlorine level naturally. So, wait for 24-48 hours and test your bathtub water after that.  On the other hand, you can reduce the chlorine level in your hot tub right off the bat if you apply neutralizer products like sodium thiosulfate. 

10 ppm chlorine in a hot tub! What Should I do?

If the chlorine level in your hot tub climbs to 10ppm, you must lower it to 3ppm before using it. Otherwise, it will bring damage to your hot tub cover and your swimsuit may start fading. Regarding this, you can use neutralizer products to lower the chlorine to optimal levels. 

How much chlorine is for a 300-gallon hot tub?

You should add 0.7 oz of chlorine granules to your 300 gallons hot tub to shock your hot tub before using it. Such an amount of chlorine will raise the chlorine level to 10 ppm. Before this, make sure your hot tub water has a balanced pH between 7.2-7.4. Also, ensure you keep your hot tub pump on to distribute the chlorine optimally. 

How fast does chlorine dissipate in the hot tub?

It takes just 15 minutes to dissipate one ppm of unstabilized chlorine level. With heated hot tub water, the dissipation process will be even faster. However, the method you will apply also determines how long it takes to drop the chlorine level. For example, it will take one-two days to reduce the chlorine level naturally. On other hand, you can lower the hot tub chlorine level right off the bat if you use chemicals like sodium thiosulfate 

Do I need to shock the hot tub after filling it?

Yes, you need to shock your hot tub after filling it if you heavily use it. Shocking your hot tub with chlorine will help to kill germs and bacteria.  The only shortcoming of shocking the hot tub is- you should wait at least 8 hours.

How often should I shock my hot tub?

How often you should shock your hot tub actually depends on how heavily you use it. Generally, you need to shock your hot tub once a week. However, you may consider shocking your hot tub twice a week if you use the hot tub more than usual. We suggest you test the pH level of your hot tub water before shocking the pool. Make sure the pH level is between 7.4-7.6.


All the methods we mentioned above work like a charm to reduce the chlorine levels in your hot tub. Among them, applying neutralizer products like sodium thiosulfate is the best. It will help you lower the chlorine levels quickly. 

However, we recommend you try out the natural methods to lower the high chlorine levels. They are eco-friendly and don’t bring any damage to your hot tub materials. 

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