Most water tests look for a handful of bacteria. This one surveys the biological community. It reports two kinds of information at once: aggregate indicators — total bacteria, total coliform, total fungi, and heterotrophic plate count — that measure how much biological activity is present overall, and organism-level identifications across 151 of the most commonly encountered microorganisms in lake systems. The aggregate numbers answer "is something changing?" The organism list answers "what is causing it?" Used together, they work like a smoke alarm followed by a fire investigation.