What does pH measure in water quality testing?

pH is a crucial parameter in water quality testing that measures the acidity or alkalinity of water. The pH scale ranges from 0 to 14, with values below 7 indicating acidity, values at 7 representing neutrality, and values above 7 indicating alkalinity.

Understanding pH is essential because it influences many chemical and biological processes in aquatic environments. For example, the solubility and availability of nutrients and metals can be affected by pH levels, which in turn impacts aquatic life. Certain species of fish and other organisms thrive in specific pH ranges; deviations can lead to stress or even mortality for these organisms.

Knowledge of pH and its implications allows for effective monitoring and management of water quality, helping to ensure a healthy ecosystem. The other options, while related to water quality, focus on different aspects: temperature measures thermal conditions, clarity assesses turbidity, and the presence of pollutants pertains to contaminants that could affect water safety and quality, but none of those directly measure acidity or alkalinity as pH does.