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What to Do If Chlorine Is Too High in a Pool

If pool chlorine is too high, stop adding sanitizer, keep circulation going, retest the water, and wait to swim until levels return to a safe range.

Archive date: this article was written for PoolSkimmer on Oct 24, 2026 and given the earlier archive date of Mar 22, 2026 so the blog reads as an organized archive. It was not published on that date.

First steps when chlorine is too high The immediate course of action if your pool’s chlorine is running high is to put a stop to adding any more chlorine or shock. The water should not be swum in until it has been tested and found to be within safe limits. Let the pump run to ensure the water is mixing and circulating as it should, then retest before making any other changes. As with the rest of your pool maintenance, Hayward would have you follow the manufacturer’s directions for chemicals and make a habit of regular testing and proper circulation.

Is the reading accurate? You may be looking at a false high if the sample was not taken right, the water was poorly mixed, or the test kit was not used as instructed. Before taking measures to bring the level down, verify the numbers:

1. Run another test on a fresh sample. 2. Be sure to adhere to the test strip or kit instructions. 3. Make certain the pump has had its time to circulate the pool water. 4. For good measure, check a different part of the pool to compare.

If the second go round still indicates high chlorine, then you can be confident that is what you are dealing with.

A safe way to reduce chlorine There is no need to introduce more chemicals; patience and circulation are often the best remedy. Whether the cause is an overzealous application of sanitizer, a recent shock treatment or simply poor mixing, the following will help:

  • Cease all use of chlorine, shock and similar sanitizers.
  • Allow the pump to do its work.
  • If your setup permits, leave the pool open so sunlight can do some of the work in bringing the level down.
  • Clear out debris and service the filter per the manual so the equipment is in good order (but turn off the pump first if you are to clean the skimmer basket).

Resist the urge to guess with another chemical to “fix” things. Wear the appropriate PPE and stick to what the product label and your manual say.

Pitfalls to avoid Some will add more chlorine at the sight of cloudy water or a strong odour, but that is a mistake that only compounds the issue. And while a smell might suggest free chlorine levels, it can be a byproduct of other conditions in the water.

Other errors to steer clear of include swimming when the levels are above what is recommended, mixing chemicals, or putting a hand in operating suction gear. Do not overlook a pump or filter that is not performing as it ought. Be mindful that high chlorine is an irritant to the skin, eyes and lungs, particularly in an indoor or unventilated space. Should anyone show symptoms after being in the water, they should get out and seek medical counsel.

Time to call in an expert? If the chlorine remains stubbornly high despite waiting and circulation, or if you are getting inconsistent results from your tests, a qualified pool professional is the one to call. This is also true if you are in any doubt about how to proceed safely, or if there are operational issues with the pump or filter that are leaving the chlorine uneven in the pool.

Sources and further reading

  • [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)
  • [Pentair U-3 skimmer manual: suction safety warnings](https://www.pentair.com/content/dam/extranet/nam/pentair-pool/pool-manuals/u-3-skimmers/395010028C.pdf)
  • [SwimmingPool.com: Cleaning the skimmer basket](https://www.swimmingpool.com/maintenance/pump&filter/cleaning-the-skimmer&pump-basket)
  • [CDC: Use pool chemicals safely](https://www.cdc.gov/healthy-swimming/media/pdfs/Pool-Chemical-Safety-USE-poster-p.pdf)
  • [CPSC: Electrical safety in and around pools](https://www.cpsc.gov/safety-education/safety-guides/pools-and-spas/dont-swim-shocks-electrical-safety-and-around-pools)

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