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.