Pool basics – the difference between pH and Alkalinity


Pool basics – the difference between pH and Alkalinity

Pool treatment entails balancing acidity and Alkalinity and maintaining an optimal pH. To take care of your Pool effectively, you must know the difference between both pH and Alkalinity.


pH is a measurement of whether a substance is basic or acidic, as you may recall from high school chemistry class. The scale goes from 0 to 14, while 7 representing neutral. Anything less than 7 is acidic, and anything greater than 7 is basic.

The pH of your Pool can be affected by anything that enters it. Rain, dirt, leaves, people etc. As a result, it’s critical to monitor your Pool’s pH levels to ensure it is within the optimal range.

Keep two pool chemicals on hand: a pH increaser and a pH decreaser. Because of how Alkalinity is adjusted, you’ll likely use less decreaser. However, it is a good idea to keep some on hand in case of an emergency.


The primary function of this pool chemical is to prevent pH from rapidly changing up and down the scale by working as a buffer, absorbing major changes in the water before they might affect the pH.

Keep a constant supply of alkalinity increaser or baking soda on hand to maintain Alkalinity. Yes, baking soda can be used to increase Alkalinity in the water!

Baking soda, like chlorine, can become an essential component of your pool maintenance. There are numerous benefits to using baking soda in your Pool to keep it clean, clear, and safe for swimmers.

Significance of pH and Alkalinity:

If your pH and Alkalinity are both low, alkalinity increaser and baking soda will raise both, which is another reason to adjust your alkalinity levels first.

Because alkalinity decreaser is not a separate pool chemical as pH decreaser will lower both if your pH and alkalinity levels are high. First, lower the Alkalinity by adding a pH decreaser. Yes, this will further reduce pH levels. Once the Alkalinity is where it should be, use a pH increaser to bring the pH back up.

This can be a difficult situation to correct. It may take several attempts to get both levels back to normal, So make changes gradually to avoid throwing things even more out of whack.

If the Alkalinity is extremely high and nothing is working, you can also try lowering it with muriatic acid.

Note: Alkalinity protects pH, so you should constantly adjust Alkalinity first, then pH if necessary. Getting the Alkalinity where it needs to be can sometimes bring the pH back into line.

What are the Optimal Levels of pH and Alkalinity in your Pool?

The ideal pH level in your pool water is 7.4 – 7.6. This creates an optimal environment for chlorine to do its job.

The recommended alkalinity range in your pool water is 80 – 125ppm for concrete and tiled pools and between 125 – 150ppm for vinyl, painted, and fiberglass pools.

If the water is out of these ranges, it can cause cloudiness and build-up of scale. We can test all of these elements and make recommendations on keeping these in balance. Don’t hesitate to call at 843 742 6437 or Email us at

Brothers Pools
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