Precise pH meter G1500 including pH electrode GE 114. Regularly measuring and adjusting the pH level is essential for all subsequent disinfection measures and should be done once or twice a week, as the pH level changes over time and depending on temperature. If the measured value is too low or below 7.0, it can cause irritation in the eyes and corrode metallic materials such as pool ladders and stainless steel lights. Additionally, so-called chloramines can form, which irritate the mucous membranes and cause unpleasant odors. In this case, the addition of pH Plus is necessary. However, if the measured pH level is too high or above 7.5, it increasingly destroys the skin's natural acid mantle, and in hard water, it can also lead to limescale deposits. Most importantly, the disinfecting effect of chlorine significantly decreases. Therefore, in this case, the addition of pH Minus is necessary.