Pool Water Balance

H2Oh! - Understanding the chemical composition of a healthy pool

Many unwanted items can be introduced to and can harm your pool, prevent chemical treatments from doing their job, make the water unhealthy, make pool water visually unappealing, or all of the above. The two most important things to remember about the healthy pools are that they must be sanitized and must be balanced.

The most efficient way to sanitize your pool and keep swimmers safe is with chlorine. Bacteria from swimmers' bodies, rain, debris, animals or other things can enter and contaminate pool water. All of these are reasons for using pool chlorine or another sanitizer.

A "balanced" swimming pool means keeping the five basic pool water components (pH, total alkalinity, calcium hardness, total dissolved solids and stabilizer) within their proper levels. These components work together to help sanitizer work more effectively. That’s why sanitizing and balancing are equally important in having a healthy pool!

Remember: Pool water balance is constantly changing - test your pool water weekly!

Total Alkalinity

Total alkalinity refers to how much alkaline is in the pool water. But you can’t fully know the importance of total alkalinity without referring to pH, because the two influence each other. Low alkaline water leads to low pH and high alkaline water leads to high pH.

Remember: Pools should have a total alkalinity level of 100 ppm.

Swimming Pool Water pH Levels

Keeping your pH levels within the proper range is important for swimmer comfort and to keep pool equipment and pool finish in good condition. pH refers to the acidity or baseness of your pool water.

Remember: A proper pH level is in the range of 7.4 to 7.6 on a pH pool water test kit's numeric scale.

On the pH pool water test kit's numeric scale, 0 to 7 reflects a low or acidic pH, and 8 to 14 means the pool has a base pH level. Low pH readings mean your chlorine will dissipate a lot quicker. High pH levels make chlorine inactive. And that means the money you're spending on chlorine is, unfortunately, wasted.

Calcium Hardness

The right amount of calcium in pool water is crucial. Too little and your pool's surface can begin "chalking" and erode. Too much and your pool water could become murky, scale formations could appear, and stubborn pool stains might begin to form.

Remember: 200 to 400 ppm is the general range for calcium hardness levels.


Stabilizer is important because it helps retain pool chlorine longer. Stabilizer is added to some types of pool chlorine to protect them from breaking down due to the harmful effects of U.V. rays. When your stabilizer level is low, you'll go through a lot more chlorine. When it's high, you may need to dilute your pool water to bring it back into the normal stabilizer range

Remember: Stabilizer has a 40 to 100 ppm ideal range.

Total Dissolved Solids (TDS)

All water contains dissolved minerals except for distilled water. When pool water evaporates, the minerals get left behind and become concentrated. As evaporation continues day after day, the pool water contains more and more concentrated minerals. Minerals in pool water make it hard for pool chemicals to do their jobs, which gives pool stains a chance to form.

Remember: Drain some water and add fresh water If you have a level of 3000 ppm or more total dissolved solids (TDS).

Balancing your pool water and keeping pool chemicals in the ideal ranges will help ensure that your pool water will not harm your swimming pool or swimmers!

  View the entire Pool Care Guide