Water require testing to determine the quality of the water which is known as water quality test. Tests are performed on the pH level, turbidity (cloudiness), chlorine residuals, dissolved solids (salts), conductivity (conductivity is a measure of electrical conductance across a solution), color or clarity. The California technology center lists a number of methods that can be used to determine the quality or purity of specific kinds of waters. Testing for nitrates is done through biological matrices such as seaweed species and plankton samples in marine ecosystems where nitrates are present at high concentrations. Examples include drinking water, industrial use, and baby formula production.
