# Implicity solvent **URL:** \ **Category:** User discussions\ **Created:** [March 6, 2023, 11:22am UTC](https://gromacs.bioexcel.eu/t/implicity-solvent/5923 "2023-03-06T11:22:31Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![rpsingh](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@rpsingh](https://gromacs.bioexcel.eu/u/rpsingh)\ **Post date:** [March 6, 2023, 11:22am UTC](https://gromacs.bioexcel.eu/t/implicity-solvent/5923/1 "2023-03-06T11:22:31Z")
GROMACS version: 2021.3 GROMACS modification: No Here post your question I have a HUGE system with many millions of atoms and \>90% of these are TIP3 water molecules. I am interested in running an implicit water simulation but as per this [link](https://mailman-1.sys.kth.se/pipermail/gromacs.org_gmx-users/2018-April/119633.html) support for implicit solvent has been removed since Gromacs 2018. Is there a way to perform implicit solvent simulations in more recent Gromacs versions (2021 or 2023)? The recent versions of Gromacs provide good GPU acceleration and hence, my intent to use the recent versions. Thanks! RPS ---
**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\ **Post date:** [March 6, 2023, 7:07pm UTC](https://gromacs.bioexcel.eu/t/implicity-solvent/5923/2 "2023-03-06T19:07:49Z")
Those options were removed because they were insufficiently accurate for modern MD simulations. They were also poorly parallelized and ultimately very slow. When native GPU support (not via OpenMM) became standard in GROMACS, explicit-solvent simulations became even faster than implicit solvent, as I recall. Thus, including relatively inaccurate and poorly parallelized features made no sense. ---
**Author:** ![rpsingh](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@rpsingh](https://gromacs.bioexcel.eu/u/rpsingh)\ **Post date:** [March 8, 2023, 2:02pm UTC](https://gromacs.bioexcel.eu/t/implicity-solvent/5923/3 "2023-03-08T14:02:50Z")
Dear Justin, Thanks for the info. Regards, Raman