Hydrochart turns a table of major-ion water chemistry into publication-ready diagrams and quality-control checks — entirely in your browser.
Plotting Piper and related diagrams and checking analyses is routine work for hydrogeologists and environmental scientists — and it usually lives in fragile spreadsheets or scattered scripts. Hydrochart does the tedious parts (unit conversion, charge balance, classification, indices) automatically, so you can go from a CSV to a clean figure in about a minute.
It's built for groundwater and surface-water professionals: hydrogeologists, environmental consultants, water scientists, and students learning hydrochemistry.
Diagrams are built on a milliequivalent-per-litre (meq/L) basis using standard equivalent weights, with the Piper diamond following the Hill (1940) construction. Hydrochemical facies are assigned by dominant ion above an adjustable threshold (50% by default).
Where TDS isn't supplied, it's estimated by ion summation (with bicarbonate counted at roughly half its mass). SAR and RSC use the standard meq/L definitions, and hardness is reported as mg/L CaCO₃.
Hydrochart's diagram methods follow the open-source Python package WQChartPy by Yang, Liu, Tang, Peeters & Ye, which implements twelve aqueous-geochemistry diagrams. If you work in Python, it's well worth using directly. Useful links:
Hydrochart has no backend and no account. Every calculation — parsing, conversion, plotting — runs in your browser. Your monitoring data, bore IDs and locations are never uploaded to a server, which matters when the numbers are confidential.
The major ions in mg/L — calcium, magnesium, sodium, potassium, bicarbonate (and carbonate), sulfate and chloride. TDS, pH and EC are optional. Column names are matched automatically, and you can edit values by hand in the tool.
No. It runs in any modern browser, on desktop or mobile — nothing to download or set up.
By summing the measured ions in mg/L, with bicarbonate counted at about half its mass — the standard ion-summation estimate. A measured TDS or EC is always preferable, and the tool marks estimated values as “est”.
Free exports carry a light “TRIAL” watermark. Pro removes it for clean, publication-ready figures. See Pricing.
The calculations use standard, well-documented methods, but you remain responsible for your results. As with any tool, sanity-check the output against a known sample before relying on it.