Which test is commonly used to assess water hardness?

The test that assesses water hardness is commonly the calcium test. Water hardness primarily stems from the presence of dissolved minerals, predominantly calcium and magnesium ions. A calcium test measures the concentration of calcium in the water, providing a direct indication of hardness levels.

Hard water typically contains high levels of calcium, while soft water has lower concentrations. Therefore, by quantifying calcium levels, a calcium test yields valuable information about how hard or soft the water is.

While pH, conductivity, and chloride tests are important for various water quality assessments, they do not directly measure hardness. The pH test determines the acidity or alkalinity of the water; the conductivity test gauges the overall ionic content, which may influence but does not specify hardness; and the chloride test identifies chloride ion concentrations, which are not indicative of hardness. These roles highlight why the calcium test is the most suitable choice for assessing water hardness.