PH is the measurement of acidity of water – measured on a scale of 0 to 14 with 7 being neutral. Not only do proper pH levels allow the other chemicals to do their work, but it is important to note that low and high levels can cause damage to a vinyl liner.

• Low pH Levels: A pH below 7.0 means the water is very acidic. Under the right circumstances with pH below 7.0, the liner can actually grow and develop unsightly wrinkles.
• High pH Levels: As the pH approaches 8.0, the water becomes very basic (alkaline). High pH greatly accelerates the aging process and shortens the life of the liner. Chlorine is also much less effective at higher pH levels. At a pH of 8.0; chlorine is only 22% effective.

Improper pH levels can lead to the vinyl liber absorbing water, causing it to expand. This can create wrinkles. It’s the same concept as spending too much time in the bathtub and your fingers become pruned and wrinkled!

Alkalinity is a measurement of the alkaline materials dissolved in water. Alkalinity in the ideal range of 100 to 150ppm helps the pH to resist fluctuations. If the alkalinity is low it can cause a “pH bounce” causing the pH level to fluctuate in and out of the acceptable range.

It is not uncommon to find metals, often called free metals, dissolved in pool water. Usually they come from source water, sometimes they come as a result of the erosion of metal pool fixtures, such as heater cores.

Free metals in pool water can cause staining of pool surfaces and inhibit the performance of water sanitizers. Ideally, there should be no metals in the water: 0 ppm. If metals are detected in your water you will need a sequestering agent to render them harmless.