Water is an important commodity during spaceflight. The Shuttle-Orbiter produces water on-orbit as a direct result of electricity generation. Hydrogen/oxygen fuel cells provide ample water for drinking, food rehydration and hygiene purposes. During the Shuttle-Mir program, water was transferred between the orbiter and the Mir space station to provide crewmembers with drinking water and water to be used for electrolysis for oxygen production. Due to the incompatibility of Russian and U.S. drinking water biocides (silver versus iodine), methods and hardware were developed to remove iodine and allow for the addition of silver biocide and minerals. At the completion of the Mir program, 5,800 kilograms of water had been transferred from the Orbiter to Mir. A refined version of the hardware used during the Mir program is now under flight development and certification for operations on board the International Space Station (ISS). This paper will describe the hardware developed for the Mir program and the modifications made to accommodate ISS operations.