How to Lower Combined Chlorine

Adding chlorine to your swimming pool every day and shocking your pool once or twice a week can’t ensure that the water in your pool is being disinfected and that the chlorine you are adding is free to kill off or becomes attached to the impurities that build up in the pool water. This type of chlorine is called Combined Chlorine. How do you lower Combined Chlorine?

When you measure the water in your swimming pool, the amount of combined chlorine in the water should be less than 0.5 PPM. If the numbers are higher, the pool may need to be shocked to get rid of the odor that comes with high amounts of combined chlorine.

By testing chlorine levels at least 2-3 times per week and knowing the signs of Combined Chlorine this type of chlorine can easily be done away with by super-chlorination or shocking your pool.


How to Lower Combined Chlorine


If the free chlorine level in your pool is lower than 2.0 ppm, it is recommended to raise the chlorine levels in order to make sure you have a strong defense against the transmission of water-borne diseases and infections that could populate your swimming pool.

There are several chlorine chemicals you can use, that include chlorine gas, chlorine tablets, liquid bleach (sodium hypochlorite), cal-hypo (calcium hypochlorite), dichlor (dichlorine), and trichlor (trichloroisocyanuric acid).

One way to lower Combined Chlorine is a process known as super-chlorination or shocking. Once combined chlorine has formed, its ability to disinfect contaminants is limited. Specifically, it takes 25 parts of combined chlorine to do the work of just one part of free chlorine. Not very efficient.

Once you know the level of combined chlorine in your pool, you will have to add about 10 times that amount of free chlorine to neutralize it.

Combined chlorine is a term used to describe free chlorine that has bound itself to a contaminant or organic material in your pool water, such as skin oil, sweat, or urine. While it is acceptable to have combined chlorine levels below 0.5 ppm, a clean and disinfected pool will have no combined chlorine present.

Having too much-combined chlorine can result in a strong chlorine odor, eye redness, and skin irritation. Total chlorine is the sum of free and combined chlorine. It is easy to monitor the total chlorine levels, but this measurement is only useful if there is no combined chlorine present in your sample.


What happens if total chlorine is higher than free chlorine?

Free Chlorine (FC) reacts with pool H2O first as Hypochlorous acid 60 to 100 x’s more effective at oxidizing microorganisms than the next stage hypochlorite ion which combines with ammonia making chloramines tested as Combined Chlorine (CC) a lesser disinfectant added to Total Chlorine (TC) residual. ……………………………………….. Read more




What is Combined Chlorine?

Combined Chlorine is the portion of chlorine in the water that has reacted and combined with ammonia, such as nitrogen-containing contaminants, and other organics that come from a swimmer’s …………………………………… more


What Should Combined Chlorine Be in a Pool


Combined chlorine is the source of the unproductive chlorine that smells and irritated eyes and skin that pool water can cause. In addition to causing discomfort and ineffective sanitization, prolonged exposure to combined chlorine can lead to asthma, allergies, and other respiratory health issues.

It is best to keep your pool’s chlorine levels above 2 ppm and below 4 ppm. If you find the chlorine level to be below this limit, the water will become a good environment for bacteria, viruses to grow and for contaminants to accumulate.

On the other hand, if the chlorine level of your pool is too high, then swimming in it will cause eye redness and skin irritation, and itchiness. In order to lower the water chlorine levels, you can either try and just wait it out or replace the existing water with new water or shock the pool water.

Combine Chlorine is the chlorine in your swimming pool that has already been combined and attached directly to the water contaminants. Chlorine levels should stay between 1.0 and 3.0 ppm.

If combine chlorine levels are higher than free chlorine levels, you should increase the amount of chlorine to better clean your pool water. The goal is to achieve a higher level of free chlorine than combined chlorine. You can purchase an inexpensive kit to give you direct readings.



Can You Swim in a Pool with Combined Chlorine?

Combined chlorine or Chloramines are an ineffective form of sanitizer recognized by an unpleasant sour chlorine smell irritating the eyes and skin of swimmers that are in the pool water close to the surface, prolonged exposure to combined chlorine…………………………… more



JimGalloway Author/Editor



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