Does the pH of a Pool Decrease When Chlorine is Added?

pool water pH

If you own a swimming pool. Or you like swimming often. Then it is super important for you to know the pH value of your swimming pool. Pool owners usually get stuck when it comes to balancing the pH level of a pool. Maintaining the pool chemistry is extremely necessary in order to maintain a healthy pool.

Also, it will keep you safe from various diseases and harmful bacteria. So, in this article, we will have a look at what basically is a pH and what is the ideal pH level you should go for. Further, we will see that does the pH of a swimming pool decrease when we add chlorine in it.

Also, we will have a look at some of the disinfectants like sodium dichloroisocyanurate and many others. Let us start with the basics.

What is pH?

PH level in water is nothing but just a measure of total acidity or alkalinity balance of water. Whether your pool is more on the acidic side or on a basic (alkaline) side. You can measure this on a pH scale ranging from 0 to 14. If a pH is lower than 7. It is acidic and in nature.

If it is above 7 then it is basic. PH 7 is considered to be neutral. Too high or too low both can cause damage to you. So, it is necessary to understand the pool chemistry and the pH level. So, that you can enjoy without any fear.

Pool pH Levels

As discussed, the earlier pool pH level is a measure of both acidity and alkalinity in water. Either it is too acidic or too alkaline. It can cause you serious damages if you do not take proper care of your pool water’s pH level. If the water is too acidic it can corrode the metals and in return can cause etching.

Importance of Swimming Pool pH Levels

Likewise, it is more towards the basic side it can cloud the water. The ideal pH for a pool is considered to be between 7.2 to 7.4. Higher or lower than that is not good for health. So, depending on the type acids or bases are added in water in order to raise or lower the pH level.

Effects of too High pH in your Pool

As we have discussed higher or lower pH values both are harmful to swimmers. So, let us have a look at the effects of too high pH in the pool:

  1. Poorer Chlorine Disinfection
  2. Skin Irritation
  3. Lime Precipitation
  4. Cloudiness

Effects of too Low pH in your Pool

Likewise, high pH value in pool water. A low pH value also has some effects on the pool. Let us what are these.

  1. Damage to Pool Liner
  2. Irritation of Eyes
  3. Mucous Membranes
  4. Aggressive Water that destroys components of the pool

Should you Lower the Pool’s pH?

If your pool’s pH level is high. Then you need to lower it. Managing the pH of a swimming pool is a never-ending process. And you need to continuously work on it. Lowering the pH of swimming is important as it is good for the overall health of a swimming pool. As discussed earlier the ideal range of pH is between 7.2 to 7.8.

Although it is more on the basic side. Less than 7.4 is considered to be acidic and more the 7.6 is considered basic. If that is the case then you have to work on it to bring the pH back to the ideal range. The higher it is the more it will be harmful. So, you have to work on it.

Does the pH of a Pool Decrease When Chlorine is Added?

Now, most of the people wonder. That can chlorine really lower the pH of the pool. Well for this, it really depends on what you use. Chlorine is a Lewis acid. So, if you add it to water. It can decrease its pH level. Some of the pools are chlorinated using sodium hypochlorite. A conjugate base of hypochlorous acid.

As it is a weak base. So, you don’t use all that much to chlorinate a pool. As a result, the pH of the pool normally stays quite near to 7.


This article is all about the pH level of swimming pools. If you want to maintain a healthy swimming pool then it is super important for you to balance the pH value of a swimming pool. You can test the pool water pH with the help of the pH scale. It ranges from 0 to 14.

If the pH is too high to low then it can cause harm to your skin and also can cause bacteria. Specifically, it focuses on either adding chlorine to water can lower the pH or not.