Nanoporous carbon materials are extensively studied for various separation applications. Among them, water desalination by means of Reverse Osmosis (RO) stands out due to it's large socio-economic relevance. Many studies are carried out in this area both computationally and experimentally. In computational studies the water simulated using different water models are prone to produce inconsistent results. In this study water desalination through hydrogen functionalized graphene nanopore is studied using different water models (SPC, SPC/E, TIP3P, TIP4P/2005). Up to 81% difference was observed in the flux estimates among the models. The water permeation rate was found to be closely related to the bulk transport properties of the simulated water. © 2019, Avestia Publishing.