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Too Much Chlorine in Your Hot Tub - How to Reduce Chlorine Levels in a Hot Tub

Updated: Jan 4, 2023

Keeping your hot tub clean and hygienic with the recommended chlorine level might be challenging. What happens if you mistakenly pour too much chlorine into your hot tub? When sanitizing your hot tub, you can either use chlorine or bromine; after all, they are both sanitizers used to destroy bacteria and germs.


While over-sanitizing a hot tub might not be a regular occurrence, it definitely happens. So can you just let the excess chlorine dissipate on its own? Yes, but remember that high chlorine or bromine levels might lead to the corrosion of your hot tub components. High concentration levels of these two chemicals can also deteriorate your hot tub cover and cause health issues like skin irritation and itchy skin.


What Are The Recommended Chlorine Levels?

When you notice a strong chemical smell from your hot tub, it could be a sign of unbalanced chlorine levels, but not always. Other water contaminants can cause such reactions too. The ideal concentration level for chlorine is 1 to 3 ppm (parts per million). If using bromine for your hot tub, the recommended level is 3 to 5 parts per million.


At What Point Are Chlorine Levels Considered Too High?


Many hot tub owners swear that there's too much chlorine in their hot tub when they begin experiencing itchy skin and irritated eyes. While their claims may be correct, everyone is different. Ideally, a chlorine level of 4 ppm is high, but some people might not be physically sensitive. However, if it goes above that, to, let's say, 10 ppm, it can lead to health complications in many cases.


What Causes High Chlorine Levels In A Hot Tub?


High levels of chlorine can result from over shocking or adding too much sanitizer during regular hot tub maintenance. The moment you add shock to a hot tub, you're introducing high doses of chlorine or bromine into the hot tub, and it'll remain that way for quite some time unless you act.


What Happens If You Go In A Hot Tub With Too Much Chlorine?


If your hot tub's chlorine or bromine level is wrong (too high), it's unsafe to go in. When you go into a hot tub with chlorine or bromine levels above 3 ppm, it's normal for you to begin noticing symptoms like nausea, vomiting, itchy eyes, and difficulty breathing.


Hot tubs with very high chlorine levels may result in chlorine poisoning, which could cause unwanted health issues. High bromine or chlorine levels cause fast degradation of hot tub surfaces. However, in line with proper water chemistry, you always need to get the chemical balance right before going into a hot tub.


How Do You Know If You Have Too Much Chlorine In Your Hot Tub?

Most symptoms people experience like irritated skin, eye discomfort, brittle hair, and change in hair colour can all happen due to pH imbalance, excess copper or other contaminants in the water. You cannot conclude that your hot tub has a high chlorine level without testing the water to confirm. As we mentioned earlier, the recommended chlorine level in a hot tub is 1 to 3 ppm. Any reading above that will harm you and damage the tub's surface.


To figure out the chlorine level of your hot tub water or spa water, you'll need chlorine test strips, and make sure you get test strips that can tell free chlorine and combined chlorine apart. The amount of free chlorine in water indicates whether or not it's at a safe level for consumption.

You can also use the DPD testing kit to measure the chlorine level in your hot tub. DPD gives a total chlorine count; it measures both combined chlorine and free chlorine levels. Compare the accurate reading from the test strips with the colour on the chart to know if your chlorine level is high, moderate or low.


How to Reduce Chlorine Levels in your Hot Tub?

There are different methods to reduce the high levels of chlorine in your hot tub. The best choice depends on the concentration of the sanitizer levels. If you notice a high level of chlorine or bromine in your hot tub water resulting from too much sanitizer, you need to act fast. You should stop adding chlorine before you try to balance it out.


Wait for the Hot Tub to Lower Chlorine Levels on its Own


This method is perfect only if you're sure you won't use your hot tub soon. Leaving your hot tub alone for a period will cause the sanitizer levels to dissipate on their own, and pretty quickly too. During this process, it's best to stay out of the water and don't add more chlorine tablets or chlorine granules.


Turn off the automatic chlorinator that injects sanitizers. Doing so will help return your hot tub water to normal. If, after two days, the chlorine level or chlorine smell doesn't return to normal, then it's time to try another method.

Pros

  • It's the easiest and most cost-effective option

  • You don't need to worry about using chemicals to deplete the chlorine levels

Cons

  • The result isn't 100% guaranteed

  • It might take extended periods before the water level returns to normal

How Long Does It Take For Chlorine To Evaporate From A Hot Tub?


Under direct sunlight, 2 ppm of chlorine will dissipate in 30 mins. So, depending on the concentration level of chlorine in your hot tub, it can take anywhere from 30 mins to 2 days for excessively high chlorine to evaporate totally.


Drain and Refill Your Hot Tub with Fresh Water

This is probably the most laborious way to lower chlorine or bromine levels in a hot tub. Once you refill the hot tub with fresh water to remove chlorine, you can proceed to add the correct amount of chlorine tablets after carefully testing it.


If you decide to refill and can't figure out the water chemistry to combat high chlorine levels, try draining and cleaning your hot tub and adding the right amount of chlorine or bromine tablets.

Additionally, draining and refilling your hot tub can take a considerable amount of time, not to mention its impact on your water bills. Adding fresh water to your hot tub can cause calcium hardness levels to increase, which you'll need to correct after diluting your hot tub water. This method is recommended for hot tub owners who wish to balance their hot tub sanitizer level while tackling sand buildup.

Pros

  • One of the benefits of this process is that it allows you to completely rinse out the unbalanced chlorine in the hot tub

  • It's easy to do, and you don't need the help of professionals

Cons

  • Adding fresh water to your hot tub water can upset the pH and alkalinity of the water

  • The process is a stressful one, and you'll spend time waiting for the chlorine level to stabilize after replacing the water

Replace Part Of The Hot Tub Water To Dilute The Chlorine

One of the first things you can do is dilute the chlorine level in your hot tub water by topping it up with clean water. Give the water time to properly circulate, then take note of the chlorine level. If you don't notice any decrease in the sanitizer levels, add more fresh water.


If you didn't lose a significant amount of water through evaporation, use a bucket to remove more chlorinated water and top it up with fresh water again. Keep repeating this process until the chlorine level has dropped to the desired level. You can use a test strip to ensure the high sanitizer levels have been normalized.

Pros

  • It's absolutely free, and you can keep making adjustments until you're satisfied

  • You don't need to use chemicals for this process

Cons

  • This process might be a bit stressful if you have to do many rounds of replacing hot chlorinated water using buckets

  • It's a stressful process of reducing chlorine or bromine levels in a hot tub

Keep Your Hot Tub Open To Let The Water Evaporate


You should do this outdoors where your hot tub will be in the sunlight. Take off the hot tub cover or spa cover and allow the chlorinated water to evaporate. This step will also reduce the water level, so you'll need to add more water after you have completed this step.


UV rays from the sun react with free chlorine to create chlorine gas that evaporates into the air. So, we recommend letting your hot tub stay under the sun for about 2 hours to lower sanitizer levels by up to 85%.


Pros

  • It's easy and cost-effective to do

  • This method has a 99% chance of working

Cons

  • It might take a long while for the hot tub chlorine to evaporate completely

  • You'll need to rebalance other chemicals in the hot tub after this process

Use A Chlorine Neutralizer

If you've added too many chlorinating granules to your hot tub, rectify it by adding neutralizer gradually to normalize the sanitizer levels. You can use a neutralizer like sodium thiosulfate to normalize hot tub water. But be careful not to drop too much into the hot tub.


Once you have added the sodium thiosulfate, proceed to add hot water, or you can run the water jets for the water to circulate properly. Do not put more doses of neutralizer than recommended by the manufacturer; a small amount will get results.

The downside of using a neutralizer is that it won't stop when it has reduced the free chlorine. It will continue until all the neutralizer has been used up, even if it means getting rid of the total chlorine in the hot tub.

Pros

  • It's one of the fastest ways to lower chlorine levels in pool water or a hot tub

  • It's readily available on the market

Cons

  • Any small slip up will result in an overdose of neutralizer

  • You cannot correctly calculate the rate at which a chlorine neutralizer works

What Is A Good Chlorine Neutralizer?


Suppose you want to normalize both chlorine and bromine levels in your hot tub. Use sodium thiosulfate. It won't disrupt the hot tub's total alkalinity, water level, or pH levels.

TIP: use a test strip to check the overall pH level of your hot tub after using sodium thiosulfate because the chemical reaction can lower the pH level.


Other Chemicals To Battle High Chlorine Levels


Yes, high chlorine levels are important for cleaning your hot tub, among other things. However, it might harm your skin and that of other bathers. In case you don't want to go all out on other methods, use chemicals like sodium ascorbate and ascorbic acid when you have too much chlorine in hot tub water.


Keep in mind that the cyanuric acid level will remain unchanged when using chemical methods to naturally neutralize the excess chlorine in a hot tub or pool water. However, putting chlorine back into the hot tub water when you want to sanitize will increase the cyanuric acid level.


Add Vitamin C

Adding vitamin C can quickly sanitize chlorine levels, so you can enjoy clean water when soaking in your hot tub. However, it won't be effective when you add a small volume; it needs to be added in large quantities. So, it makes more sense to use it as a second step after trying out any of the methods mentioned above.

Pros

  • It's a very effective fix for high chlorine levels

  • This process takes less time than other methods

Cons

  • It's a bit expensive to use this method

  • You'll need to add vitamin C in large quantity

Does Lemon Juice Neutralize Chlorine?


Lemon juice contains a considerable amount of vitamin C, so when used in large amounts, it can be helpful to remove excess chlorine instantly. However, it might be a bit difficult and expensive to get enough pure lemon juice that'll considerably affect sanitizer levels. Use a test kit to check the chlorine level after using lemon juice to fix it, and if it doesn't work, try using another method.


Will Baking Soda Lower Chlorine Levels In A Hot Tub?


Baking soda doesn't reduce chlorine levels in a hot tub. It increases the pH and alkalinity of the hot tub water or spa water, whichever one. When added to chlorinated water, baking soda increases the pH level so other chemicals can react faster.


So, directly, it doesn't reduce bromine or chlorine levels in a hot tub, but it helps other chemicals neutralize it.

If the pH level of your hot tub water is below 7.0, we recommend you add 4lbs of baking soda. This will raise the acidity level of the water.


Does Hydrogen Peroxide Lower Chlorine Level?


High chlorine levels can be naturally controlled using hydrogen peroxide (an oxidizer), but be sure to get the one specially designed for hot tubs. Get the correct one, and you can go in for a soak after you have completed the process. People assume that you can use hydrogen peroxide at any time, but that's not true. Using hydrogen peroxide will be a waste of time if the pH level isn't higher than 7.


Pros

  • It's an inexpensive way to reduce chlorine levels in a few seconds without ruining the soft surfaces of your hot tub

  • Hydrogen peroxide can be gotten from almost any local store

Cons

  • It lowers the pH level of hot tubs

  • If your pH level isn't higher than 7, hydrogen peroxide won't be effective

How Long Does It Take To Lower Chlorine In Hot Tubs?

After using your test strip to confirm there is lots of sanitizer floating in the hot tub, the next step will determine how long it'll take before you can have a nice, warm soak. Whatever method you choose depends on the level of chloramines you have in your hot tub water.


Regardless of what method you use, you'll need to ensure the chlorine level is balanced (1-3 ppm). Ensure the water is tested using a test kit before entering the tub. Generally, it should take anywhere from 1 hour to 48 hours for the chlorine to dissipate completely. If you decide to shock your hot tub, it'll take about 24 to 48 hours to reduce the chlorine level.


Conclusion


Yes, chlorine is naturally used to kill germs and bacteria in hot tub water, spa water and pool water. However, excess levels of sanitizers like bromine and chlorine cause damage to not just your health but your tub as well. If you happen to over-chlorinate your tub by mistake, many options are available to filter out the excess chlorine.


Lowering the chlorine levels of your tub water isn't up for debate unless, of course, you don't want to have an enjoyable experience. Check out our website for more information and a wide list of chemicals for hot tubs.

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AUTHOR

Jess Court

I'm Aqua Warehouse Groups Marketing Officer - overseeing all things news worthy in the hot tub industry, with tips and tricks that are bound to make a splash.

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