These guides explain what each diagram Hydrochart produces actually shows — which axis means what, how a sample becomes a point, and what the patterns tell you about water type, mixing and geochemical process. Every guide uses the same meq/L conventions as the plotter.
Pick a diagram
Each diagram answers a slightly different question. The Piper and Chadha plots classify water into types; Stiff and Schoeller compare samples visually; Gibbs, Durov and the bivariate plots point at the process — weathering, evaporation, mixing or ion exchange.
A note on units
Every diagram here works on a milliequivalent-per-litre (meq/L) basis: concentrations in mg/L are divided by each ion's equivalent weight so cations and anions can be compared and charge balance checked. Hydrochart does that conversion for you; these guides assume it's already done.