Too Much Chlorine In Pool? Here Is What You Need To Know And Do About It

Last Updated on January 25, 2022

Owning a pool is challenging and tricky. You have to apply proper care practices and maintenance to ensure your swimming pool is clean and safe. There are walls and fixtures to brush, leaves and debris to skim, and machinery to keep running. On top of that, you also have to balance your pool chemistry.

For new pool owners, all these tasks can be daunting, especially when it comes to chemical reactions and maintaining proper chlorine levels. Since it kills germs, algae, and bacteria, many tend to add more chlorine to make their pools cleaner. However, putting too much chlorine in pool is dangerous and can cause many health concerns.

So what if you’ve already added too much chlorine in your pool? What can happen? More importantly, what can you do, and how do you fix it? Are there alternatives for chlorine? These are all very common questions that pool owners ask, and we’re here to answer all of them.

What Happens If You Swim in a Pool with Too Much Chlorine?

Before we proceed, it’s important to know the dangers of having an over-chlorinated pool. While most reactions are mild and will disappear as soon as you rinse the pool water off, too much chlorine is still dangerous for swimmers. See, high chlorine levels alter the pool water’s pH, making it more acidic. This can have adverse effects and can cause the following reactions:

  • Dry skin and hair
  • Skin irritations or itchy skin
  • Rash or hives
  • Eye irritation
  • Coughing
  • Pain in the nose or throat
  • Trigger asthma
  • Lung irritation

Aside from that, high levels of chlorine can also damage your swimming pool. The higher the acidity of the water, the higher chances of it causing corrosion. This can affect your pool’s metal piping and surfaces, including liners, concrete, and tiles. Furthermore, your pool equipment and accessories can also corrode and get damaged.

How Much is Too Much Chlorine in Pool?

Chemical Recommended RangeAcceptable Range
Chlorine2 – 5 ppm1 – 5 ppm
pH7.4 – 7.67.2 – 7.8

Chlorine and pH work hand in hand to disinfect your swimming pool. Even if you have the right chlorine level, but the pH level is too high, the water can still be unsafe to swim in. This is because chlorine loses its effectiveness in acidic water. So it’s important to check not only the chlorine concentration but the pH level as well.

According to the Centers for Disease Control and Prevention (CDC), the recommended free chlorine concentration is at least 1 parts per million (ppm) and pH of 7.2 to 7.8. If you are using cyanuric acid or chlorine products with cyanuric acid, the pH level should be between 7.2 to 7.8, and the free available chlorine concentration should be at least 2 ppm. Generally, the ideal chlorine level ranges from 1 to 3 ppm, with 4 to 5 ppm still within the acceptable range. Anything higher can cause red eyes and swimmer’s itch, and above 6 ppm is already considered unsafe. 

Free chlorine refers to the chlorine that is free or available to eliminate harmful microorganisms in pool water. It’s the amount of chlorine that has not yet been combined with chlorinated water. 

Take note, however, that there will be times when you have to super chlorinate your pool to remove bacteria, chloramine, and algae. In this process, the chlorine level will be raised to 10 to 20 ppm. But make sure that no one will be swimming as these levels can irritate or burn the skin and eyes.

How to Tell if Your Pool Has Too Much Chlorine?

Strong Smell

Contrary to popular belief, you can’t smell if there’s too much chlorine. In fact, what you’re smelling isn’t even chlorine. It’s chloramines, which is the mixture of chlorine with dirt, sweat, sunblock oils, cosmetics, urine, and other human bodily wastes. See, unhygienic pool habits like not showering first or peeing in the pool use the available chlorine quicker, resulting in a stronger smell.

So if you notice a chemical-like smell from your pool, it means that most of the chlorine is used up. Thus, you’ll need to add more, not less. This will eliminate the chlorinates, which is causing the “chlorine smell”. Also, remember that a properly maintained pool will not have any odor at all. 

Cloudy Water

Cloudy water is another sign people look out for to know if they’ve added too much chlorine. While it’s true that too much chlorine can cause pool water to turn cloudy, it may not be the only reason. See, any imbalance in the water’s chemistry gives it a murky appearance, including high calcium hardness, high alkalinity, and high pH. That said, you won’t know for sure if high chlorine is the actual reason behind your cloudy pool water. So checking on the appearance of your pool water alone is not a reliable way to know if there’s too much chlorine. 


Testing is the best and only way to know if your pool has a high chlorine level. For some, they take samples of their pool water and have it tested at the local pool and spa dealers. While this works, it can get expensive and inconvenient real fast. So if you want to save a couple of dollars, consider testing on your own. 

For the most accurate results, you should use a DPD test kit. This will measure the pH, and free, combined, and total chlorine as well as ozone and bromine levels. It’s the test procedure preferred by many due to its reliability and consistency. 

Don’t have a DPD test kit yet? Check out Taylor Technologies Inc K-2006. It’s a complete service drop test kit that uses DPD powder for chlorine testing. If you prefer using a liquid reagent, you can choose the Taylor K-2005 Test Kit instead. On the other hand, if you’re looking for a more affordable DPD testing option, then we suggest the Poolmaster Water Chemistry Case Premiere Collection 5-Way Swimming Pool & Spa Test Kit.

As an alternative, pool owners can also use test strips. This is the fastest and easiest way to check your pool water’s chemistry. Just dip the strip in the water, check the color results, and you’re done. They’re a lot cheaper than DPD test kits too. But keep in mind that they are less accurate.

If you’re interested in using a test strip to check your pool water’s chlorine level, we suggest the AquaCheck Select 7-in-1. It contains 50 strips per bottle and can measure free chlorine, total chlorine, pH, total hardness, total bromine, total alkalinity, and cyanuric acid levels.

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How to Lower Chlorine In Your Pool?

After performing the test, you would then have to determine the best treatment method possible. This will depend on the scale of the problem and how soon you need to use your pool.

For instance, if your pool water’s chlorine level is only slightly high or around 4 ppm to 5 ppm (which is within the acceptable range) and if you’re not planning to use the pool anytime soon, then the easiest way to lower the chlorine in your pool is to do nothing. That’s right. Waiting for an hour or so will usually get your chlorine levels within the ideal range. 

However, if your chlorine level is significantly high and you’ve got a pool party coming up, then you have to do the following: 

Stop Adding Chlorine

When your test results show that your chlorine is just slightly higher than the recommended range, you can easily lower your pool’s chlorine levels by not adding any more chlorine. While this may seem obvious, some pool owners forget to check other chlorine sources. A chlorinator, chlorine dispenser, or chlorine feeder, for example, should be turned off. If you have a chlorine floater, make sure to remove it from your pool as well. If your skimmer has a chlorine tablet, take it off. 

Use Sunlight

If you still have a couple of hours to spare before you need to use your swimming pool and if it’s all bright and sunny, you can simply uncover your pool and let the sun do the work. The ultraviolet rays the sun releases can destroy chlorine. In just 2 to 3 hours, direct sunlight can reduce a pool’s chlorine level by up to 90%. If you’re going to use this method, make sure to monitor the pool water after a few hours to know if it’s safe to swim.

Add Other Pool Chemicals

In a rush and need to lower your chlorine levels quickly? If so, then add other chlorine neutralizing chemicals. This will effectively and rapidly reduce the level of chlorine in your swimming pool. You can use Sodium Sulfite and Hydrogen Peroxide. Sodium Thiosulfate will also do the trick and if you’re interested, check out the Pool Dechlorinator Sodium Thiosulfate from Cesco. Or if you want, you can simply buy a pre-packaged chlorine neutralizer like the In The Swim Pool Water Chlorine Neutralizer.

No matter what chemical you choose, make sure to follow the instructions. For very high chlorine levels, you may need to add a second dose of chemicals. 

Add Water

Partially draining water from your pool and adding fresh water can help lower the level of chlorine in your pool. This method is called dilution and it’s only ideal if your chlorine level is slightly higher than the recommended range. If it’s too high, then this is not a viable option due to the amount of freshwater needed. 

While diluting your pool can work, it’s not the most practical solution. For one, it takes a lot of time. It can also significantly increase your water bills. Besides, it disrupts your alkalinity, calcium hardness, pH, and other chemical levels. So you’ll need to monitor each one again and readjust. 

Turn on the Heater

If you have a heated pool, you can raise the temperature to around 90°F to 10°F above the recommended level. But do so only for a short time. This will cause bacteria to multiply, which will then use more chlorine. For this method, make sure to monitor the chlorine levels throughout the day. 

Now remember, “Your pool’s water chemistry can change on a daily basis”, says POOLCORP Chemical Specialist Melissa Bushey. She also reminds pool owners such as yourself to “test and balance each week” to achieve that comfortable sparkling clean water you’ve always wanted.

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