# No more replaceable solvent!

**URL:** <https://gromacs.bioexcel.eu/t/no-more-replaceable-solvent/669>\
**Category:** User discussions\
**Created:** [August 15, 2020, 12:19am UTC](https://gromacs.bioexcel.eu/t/no-more-replaceable-solvent/669 "2020-08-15T00:19:53Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![L\_k](https://avatars.discourse-cdn.com/v4/letter/l/ebca7d/32.png) [@L\_k](https://gromacs.bioexcel.eu/u/L_k)\
**Post date:** [August 15, 2020, 12:19am UTC](https://gromacs.bioexcel.eu/t/no-more-replaceable-solvent/669/1 "2020-08-15T00:19:53Z")

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I am trying to simulate increased salt concentrations, but in adding ions to my system using gmx genion and -conc I run into the error: No more replaceable solvent! This is a 30x30x30nm box at 2M-5M concentration. Has anyone run into or resolved this issue? Any advice is greatly appreciated. Thank you.