What does pH measure?

pH is a measure of the concentration of hydrogen ions in a solution. It reflects the acidity or alkalinity of that solution, with lower pH values indicating higher concentrations of hydrogen ions (more acidic) and higher pH values indicating lower concentrations of hydrogen ions (more alkaline). This measurement is crucial in various applications, including water quality testing, because even slight variations in pH can significantly impact chemical reactions, aquatic life, and the effectiveness of disinfectants, such as chlorine. Understanding pH allows water operators to maintain water treatment processes effectively and ensure safe drinking water standards are met.