What kind of taste could indicate a problem with algae in water?

A grassy or fishy taste in water can indicate the presence of algae, specifically when certain types of algae bloom. These blooms can release organic compounds known as geosmin and 2-methylisoborneol, which are responsible for earthy and fishy flavors that are often associated with algae. The presence of these compounds can be a sign of deteriorating water quality and potential health risks if ingested.

Other tastes, while they may signal various issues, do not specifically indicate the presence of algae. For example, a sweet taste could suggest the presence of certain contaminants like artificial sweeteners, a metallic taste often points to corrosion of metal pipes, and a bitter taste could be attributed to various minerals or pollutants. Each of these tastes may suggest different water quality problems, but the grassy or fishy flavor is the hallmark indicator of algal contamination.