PHREEQC version 3

Most important new features (relative to version 2.18):

  • Precise calculation of gas-solubilities with the Peng-Robinson Equation of State.
  • Pressure effects on mineral solubilities.
  • Multiple USER_GRAPH's with flexible -plot_xy function.
  • INCLUDE$ that allows to read in other files into the input file, and to execute them.
  • .._MODIFY keywords that permit to change any model property.

Goto the download site, with the install file for phreeqc version 3.


Notepad++ is recommended for writing, editing and running PHREEQC3 input files. It provides:

   • syntax highlighting
   • autocompletion
   • calltips for BASIC functions and KEYWORDS
   • colored numbers (1 and l are differently colored!)
   • bracket matching: print (1 + 9.0) / (9 + 1.0)|
   • (un)commenting multiple lines at once
   • column editor for easy BASIC line renumbering
   • shortcuts: e.g., Ctrl+F6 calls PHREEQC on the current file
   • file recognition on extension: .ppi .pqi .phrq .phr .dat .out
   • comments and sections in between '#[' and '#]' can be folded up.

An adapted version of Notepad++ will be installed along with phreeqc version 3 by the installer, see the download site.


  • PHREEQC help lets you make a quick start.

    (This file is extracted in c:\phreeqc\manual by phreeqc3.Installer.exe.)

    In Notepad++, press Alt+F6 to start the help.

  • PHREEQC help

  • David Parkhurst's site has other PHREEQC versions and the phreeqci GUI.

  • Vincent Post's PHREEQC-2 for WINDOWS uses the obsolete version 2.18, but the interface is inviting and the keyword templates may be helpful when starting.

  • David Kinniburgh's PhreePlot allows to make accurate pe-pH diagrams and has a wealth of options for plotting other chemical data, for example:

    pe-pH-As pe-pH-As+sorbed species As sorbed species as function of P_CO2 and PO4
    See the gallery of PhreePlot for more examples.

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