The ideal pH range for pool water is about 7.4 to 7.6 pH with pH values of 7.2 to 7.8 being acceptable. Spas should be maintained within a pH range of 7.2 to 7.8.
Below: Kittiwake provide a wide range of pH Test Meters
Info Centre >> Water Treatment Technical Manual >> 4. Applications Related/General Information >> 4.4 Measuring pH in Pool Care
pH has an important impact on sanitizer effectiveness, pool and spa surfaces, pool equipment and the swimmer. There are common problems associated with pH levels that are too high or too low, as detailed in the table below.
Balanced water is a term used to describe the ideal condition of a pool. The water is balanced if it has just the right amount of pH, pH buffers, calcium and magnesium hardness, and dissolved solids.
In order to determine the pH and disinfectant concentration in your pool water, tests should be conducted regularly. Public pools should test their water every day before the pool is opened, then at least once during the morning, afternoon and evening sessions. Testing intervals should be no longer than four hours when the pool is open.
Consult pool and spa supply stores or pool maintenance specialists for help in raising or lowering pH levels in the pool water. Soda ash and sodium bicarbonate are helpful in increasing pH. Liquid muriatic acid works best to lower pH effectively.
Water Treatment Testing: Swimming Pools & Spas
*Information Provided Courtesy of Eutech Instruments Pte Ltd Copyright © 1997
| pH levels - possible problems | |||||||||||||||||||
High pH Readings |
Low pH Readings |
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| Poor sanitizer efficiency | Poor sanitizer efficiency | ||||||||||||||||||
| Cloudy water | Skin and eye irritation | ||||||||||||||||||
| Shorter filter runs | Corroded metals and equipment | ||||||||||||||||||
| Scale formation | Stained plaster | ||||||||||||||||||
| Skin and eye irritation | |||||||||||||||||||