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Predominance diagrams

Speciation plots

Reaction path calculations



Weekly average CO2 at Mauna Loa

Jul 7, 2024
426.25 ppm
1 year ago
422.37 ppm
10 years ago
399.92 ppm
270 ppm
Year-on-year change
3.88 ppm


PhreePlot is a program for making geochemical plots and fitting geochemical models to observations with PHREEQC.


PhreePlot contains an embedded version of PHREEQC. PhreePlot sits on top of PHREEQC and makes it relatively straightforward to do repetitive PHREEQC calculations, the type of calculations that are often needed to make a plot. PhreePlot uses tags placed within the PHREEQC input file to identify places where substitutions are to be made and has several looping mechanisms to control the values substituted. It also contains software for generating Postscript (ps) plot files and optionally a bundled version of Ghostscript for converting these to a variety of other image formats. In addition to normal PHREEQC-type calculations, PhreePlot can be used to generate predominance diagrams, make 2D-contour plots and to fit PHREEQC models to observations using various optimization routines.



Reviews and calculations



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The following are acknowledged for their major contributions to the code in PhreePlot:

A full list of Acknowledgements is given in the PhreePlot Guide.


Please send David Kinniburgh ( bug reports and any comments on the Windows Installer, program or documentation. Examples to add to the Gallery are also welcome.

You can automatically check whether you have the latest version of PhreePlot installed each time you run PhreePlot by setting the keyword 'checkForUpdate' to TRUE in the settings file ( pp.set).