Water Chemistry /
How to Lower Chlorine in a Pool Safely
To lower chlorine in your pool, stop adding sanitizer, keep the water circulating, retest the free chlorine, and let time, sunlight, or dilution do the rest.
Archive date: this article was written for PoolSkimmer on Oct 23, 2026 and given the earlier archive date of Jan 30, 2026 so the blog reads as an organized archive. It was not published on that date.
Lowering chlorine in your pool
The most prudent course of action when the chlorine is running high is to simply cease adding sanitizer and let the pool do its work. Keep the system circulating and put off any swimming until you have retested the water to be sure. For the most part, sunlight will take care of excess chlorine on its own. Should the numbers remain elevated, it is best to keep the pool closed until they are within a safe range.
Where to begin?
A proper water test is the first order of business. While a test strip is useful, make certain you are looking at free or total chlorine as required. Do not be swayed by odor; a potent chemical scent can mean the water chemistry is out of whack, not necessarily that there is an overabundance of chlorine.
Before you make any moves: - Put a halt to adding chlorine. - Let the pump run for circulation. - Consult the equipment manual and chemical labels. - Make sure to don the right PPE with pool chemicals. - The skimmer should only be checked once the pump is off.
The safest approach to reducing levels
There is no need for guesswork when it comes to bringing down chlorine. Here are some practical methods:
1. Rely on the sun With the cover off, sunlight will break down the chlorine. It is often the simplest solution if the level is not excessively high.
2. Maintain circulation Good circulation is key to overall maintenance and keeping the water well mixed. Ensure the filter and skimmer are clean so the system can perform as it should.
3. Dilute the water In some instances, draining part of the pool and refilling with fresh water will reduce the concentration. This is only advisable if your local regulations and the pool manual allow for it.
4. Test before you swim Give the water time to settle and then test again. The fact that it looks fine is no guarantee the chlorine is at a safe level.
Is high chlorine the whole story?
If the chlorine does not come down after you have stopped putting it in, try to find the root cause rather than applying haphazard remedies. You may be dealing with an overdose from the chlorinator, a faulty or old test strip, or perhaps the pH and alkalinity are unbalanced, making the water feel harsh. Cyanuric acid can also alter how the chlorine acts.
Any strong smell, irritation or cloudiness could be indicative of a wider problem with the water balance. In such cases, a full review of the chemistry is warranted.
Things to avoid
Do not be tempted to add household chemicals or force a quick fix in disregard of the manuals. Unless a product label tells you to, stay away from mixing chemicals. And never put anything into an operating suction outlet.
When you go to the skimmer basket, the pump must be off. An electrical fault near the equipment means everyone stays out of the water and a professional is called.
Time to call in an expert?
It is wise to contact a qualified pool professional under these circumstances: - The chlorine has not abated after several days - You cannot get the water to balance or it is causing irritation - You are in doubt about your readings for free or total chlorine - There is reason to think the filtration or circulation is at fault - A chemical or electrical error is suspected
Speed is not as important as safety. Until the water has been tested and proven safe, do not swim.
Sources and further reading
- [Hayward: Weekly pool maintenance](https://www.hayward.com/maintenance/weekly-pool-maintenance)