How to Lower Chlorine in Pool (5 Methods)

How to Lower Chlorine in Pool

Chlorine plays a crucial role when it comes to keeping your swimming pool sanitized. Hence, it is one of those pool chemicals you can be sure you will need to buy a lot unless you have a chlorine-free pool.

However, as vital as it might be, you need to keep it at optimal levels because too much of it will cause more problems and will not be effective at sanitizing the water.

As a pool owner, it is crucial to understand the optimal chlorine level to maintain and how to lower it if there is too much.

What’s the Optimal Level of Chlorine in Pool 

There is a common misconception that if you can smell chlorine in your pool, you have too much. The truth is that what you are smelling is chloramines, which is a compound that forms when chlorine binds to body excretions like sweat.

Knowing the optimal levels you need is the most reliable way to tell when you have too much chlorine in your pool. That said, the optimal level of chlorine in pool water is between 1 and 3 ppm, regardless of the system you use to chlorinate the water.

When chlorine levels are above 5 ppm, the swimmers are likely to experience eye irritation, get itchy skin and the hair also dries out. If the levels go beyond 10 ppm, swimsuits will start fading and degrading, and things like pool covers or liners also get damaged.

5 Ways to Lower Chlorine in Pool 

The correct method to lower chlorine in your pool depends on the actual level you have. So it is always important to measure it with reliable test strips like the AquaChek 7-Way Test Strips before anything else. Here are 5 of the most common methods.

Method 1: Expose the Pool to the Sun

Before adding chemicals to your pool to lower chlorine, it is always better to try a more natural approach, like exposing the pool to the sun. This method will not cost you anything, and it eliminates the need to add more chemicals to your water.

Exposing the pool to the sun’s UV rays will lead to a breakdown of chlorine within a short time, reducing the level significantly. UV rays will reduce the chlorine level in the pool by up to 90% in just a couple of hours. However, this is only so for unstabilized chlorine.


  • Does not cost anything
  • No chemicals needed
  • Can reduce chlorine levels quite fast


  • Hard to control how much chlorine you remove
  • Does not work well for pools with a stabilizer
  • Not ideal for indoor pools

Method 2: Dilute Pool Water

Diluting your pool water is another simple but effective method of lowering chlorine levels in your pool water. By simply draining some water from the pool and replacing it with freshwater, you can quickly restore the chlorine to the optimal level.

With this method, you will not need to use any chemicals, and so besides a slight increase in water bills, it is pretty affordable. However, draining and refilling the pool takes some time, and you will also need to rebalance the pool chemistry afterwards as it disrupts things like pH.


  • No chemicals required
  • Does not cost much


  • Takes quite some time
  • It can disrupt pool pH

Method 3: Use Hydrogen Peroxide

Hydrogen peroxide also lowers chlorine levels in pools. Although almost any type can be effective, choosing one with a higher concentration for use in pools is better to ensure maximum effectiveness.

Hydrogen peroxide is an oxidizer that will react with chlorine to give off water and oxygen as byproducts.

However, it will work best when you have the pool pH at 7.0, and so before using it, you should test the pH level and adjust it to the ideal level. Also, you will need to work on the pH afterwards, as adding hydrogen peroxide will cause a disruption.


  • Inexpensive chemical
  • Easy to find


  • Works well at specific pH only

Method 4: Use the Pool More

Sometimes just using the pool more is effective enough at bringing down the chlorine levels. The primary purpose of chlorine is to deal with contaminants. Therefore, swimming more or having many people use the pool brings lots of contaminants, and some of the extra chlorine will be used up to deal with them.

However, make sure the levels are not too high. Otherwise, you might end up putting the swimmers at serious risk. The pool should be still safe to use, provided the chlorine level is not over 5 ppm and having several people use it can reduce chlorine by at least 1 ppm.


  • Completely free
  • No harsh chemicals needed


  • Not beneficial for very high chlorine levels

Method 5: Use Commercial Chlorine Neutralizing Chemicals

If the methods above do not give you the results you are looking for, you should try chlorine neutralizing chemicals. The most common ones are sodium sulfite and sodium thiosulfate, and they will provide a quick fix when you want to bring down chlorine levels fast.

Most chlorine neutralizers will not affect the alkalinity, pH and even water hardness, meaning you will not need to rebalance the pool chemistry afterwards. However, they can be expensive depending on how much you use, and some can be pretty volatile.


  • Most types will not disrupt alkalinity or pH
  • Faster chlorine lowering


  • Can be expensive
  • Some chemicals are highly volatile

Bottom Line 

High levels of chlorine will make your swimming pool unsafe and uncomfortable to use. Therefore, it is essential to lower it promptly.

There are several ways of lowering chlorine, but you should always start by trying natural ones, such as exposing the pool to the sun or diluting the water.

Aim to keep the chlorine levels between 1 and 3 ppm for effective sanitization and ensure swimmers’ safety.

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