Add 5 drops of the pH liquid reagent and swirl gently for 10 seconds.
Hold the white part of the color chart against 1 side of the test vial and look through the opposite side to compare colors. Best results are obtained by using natural daylight.
If the color is somewhere between 2 values then the pH is also in between those values.
In case the pH is too low the alkalinity might be too low. However, never increase the alkalinity to a value higher than 12 dKH or 4.3 meq/L.