Learn which plants thrive in your Hardiness Zone with our new interactive map!

How to Read a pH Test for a Pool

By John Brennan ; Updated September 21, 2017
Testing your pool's pH is an important part of pool maintenance.

Testing pH is a crucial part of pool maintenance. Not only is it important but it's easy, too; most pool supply stores sell pH test kits with the chemicals you'll need. Generally, reading your pH test entails a couple of simple steps to get a result -- then comparing this result with the color codes supplied by the manufacturer. Before you can test your pool pH, however, you need to know your pool chlorine level. Many pool test kits include equipment for testing both chlorine and pH, so it's usually a good idea to test chlorine first.

Add pool water to the viewing tube of your test kit until it reaches the mark on the tube.

Add sodium thiosulfate using the eyedropper provided in the kit. Use one drop of sodium thiosulfate for each part per million of disinfectant in your pool -- e.g., for each part per million of residual chlorine or bromine.

Add five drops of indicator (unless the manufacturer requires a different amount). Close the tube and gently swirl.

Compare the color of the tube with the color chart provided by the manufacturer. The pH value next to the matching color on the chart gives the pH of your water. If the color of the water is in between two of the colors on the chart -- if the chart gives the pH for peach and orange colors, for example, but your sample is peach-orange -- this means the pH of your water is between those two values.

Compare the color of your water with the acceptable range on the chart. If the color is within the acceptable range, your pool pH does not need to be adjusted. If it is outside the range, your pool pH needs adjustment.


Things You Will Need

  • pH test kit


  • Not all manufacturers use the same reagents, so the color charts may not be the same for all kits -- don't attempt to mix and match chemicals and charts from different kits.

About the Author


Based in San Diego, John Brennan has been writing about science and the environment since 2006. His articles have appeared in "Plenty," "San Diego Reader," "Santa Barbara Independent" and "East Bay Monthly." Brennan holds a Bachelor of Science in biology from the University of California, San Diego.