What Happens if You Go in a Hot Tub with too Much Chlorine

Chlorine in water protects you from germs, so more Chlorine means more protection, right? Wrong. Excess Chlorine in your hot tub protects you from bacteria but also affects your skin, eyes, and breathing adversely.

If you go in a hot tub with too much Chlorine, your skin can become itchy and red, your eyes might sting, and you can experience breathing difficulties ranging from detecting a pungent odor to having a respiratory blockage.

In this article, you will learn more about the nuances and severity ranges of each one of the following effects of Chlorine:

  • Itchy skin and rashes 
  • Redness in eyes
  • Stinging sensation in the eyes
  • Breathing difficulting

Itchy Skin

Chlorine’s anti-bacterial and anti-microbial properties are beneficial to us, but it is a chemical that has a proportion-driven “bite.” It kills bacteria because it is present in abundance compared to the weight and size of a single bacterium. 

Bacteria are ten times smaller than our skin cells. This means that the moment chlorine exceeds its average hot tub concentration by ten times, it starts affecting your skin the same way as it affects bacteria.

The “too much chlorine” stage comes much earlier and is indicated by the redness of the skin. When you add twice as much Chlorine as usual in your hot tub, your skin gets red upon jumping in. But since redness can also be the result of heat, many people miss this sign until their skin begins to itch. If your skin is itchy once you get out of the hot tub, you should consider reducing its chlorine concentration.

Difficulty in Breathing

This is an umbrella label for a plethora of respiratory issues caused by chlorine fumes. If you’ve been in a public swimming pool, you know the odor of over-chlorinated water. When Chlorine is present in an even higher concentration in your hot tub, you can expect much more than a pungent odor. The following table shows the effects of chlorinated water on your respiratory system at different levels of concentration.

Chlorine concentrationEffectSeriousness / Solution
AverageMild odorNot serious at all
Slightly above averagePungent smellWashing yourself with filtered water becomes a more serious demand
3 times the averageNausea and gaggingSerious. Immediately get out of the pool and wash yourself. Walk in a park or other green-adjacent areas.
4 times the averageCoughingQuite serious. Get an oxygen mask if possible. 
6 times the averageDifficulty in breathingMedically serious. Call your doctor and use an inhaler with chlorine toxicity medication.
8 times the averageVomitingThis is serious enough to call emergency services. It can have a lasting impact on your lungs.
9 times the averageDrowsinessBy this point, the exposed person’s skin is also affected. It is an ambulance-worthy level of seriousness. 
10 times the averageLoss of consciousnessIn a swimming pool, this concentration doesn’t have as serious a result as in a hot tub. If someone loses consciousness in the hot tub due to chlorine exposure, he must be taken to the hospital immediately.

Itchy Eyes

Finally, chlorine exposure can also affect your eyes. This seems more believable in the context of swimming pool chlorination but not in a hot tub. You might believe your eyes are safe just because you are in a hot tub and not dipping your head in the water. The last section covered the effects of chlorine fumes. So it is worth keeping in mind that chlorine vapor can also have an impact.

Of course, if you dip your head in overchlorinated water, your eyes will get red and itchy much quicker than if you keep it up. The itchiness of the eyes can be negated with the right eyewash. Even a safe level of Chlorine in your hot tub can result in a slight itch in your eyes. I find Medi-First Eyewash worth keeping in case that happens. An eyewash is almost mandatory for hot tub owners who have kids.

Kids love to dip underneath, and it is far more fun to allow it than to force them to keep their heads up. Having a reliable eyewash gives you the security to let it happen. But please avoid having your kids in the hot tub even if you have the slightest doubt that you put too much Chlorine in.

What To Do if You Have Too Much Chlorine in Your Hot Tub?

Now that you’ve learned the key effects of Chlorine on your skin, eyes, and breathing, you might want to reverse the over-chlorination of your hot tub. But is that even possible?

If you have too much Chlorine in your hot tub, you can let the tub sit in the sun for a week or two. This will get rid of the Chlorine. Sunlight is a natural counter for Chlorine which is why you need to add Chlorine over and over. 

The advantage of this method is that it is the lowest effort solution for over chlorination. The drawback is that it requires high sunlight exposure, which is not available in some regions. An even more important disadvantage to most hot tub owners is that the period required to let the pool sit is too much.

If you cannot wait that long, you have a second purchase-free solution. Drain half the hot tub and refill the rest. This is a classic dilution tactic that can get you soak-ready within a day. It is a cost-intensive solution and is limited by your drainage capacity. 

If you don’t mind making a purchase that can minimize the effort and amp up the dechlorination of your tub, add Sodium Thiosulfate to your hot tub and let the Chlorine vanish. Cesco Solutions Pool Dechlorinator (which consists of Sodium Thiosulfate) is an excellent option in this regard.

Since it is a chemical that’s hard to test for the average consumer, it is wiser to depend on a big-name manufacturer that stands to lose more by adding impurities than by selling the pure product. Cesco Solutions is a big enough company to inspire a sense of trust. But that’s not why I prefer this neutralizer. It’s mainly because it isn’t a liquid, and crystals are easy to measure.

Final Thoughts

Chlorine can have serious consequences when it is used in excess in a hot tub or a spa. But its benefits outweigh its consequences up until one adds double the required Chlorine. So when you add Chlorine to your hot tub, you can err on the side of more, but within reason. The moment you detect an unusually strong chlorine odor, you need to dial back.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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