Consistent and reliable water quality is the key to a successful dialysis treatment. The quality of dialysis water in terms of dissolved solids in it and the microbial load is strictly specified by European and American standards (AMMI standards). Reverse osmosis units ensure the quality of water intended for hemodialysis machines. The water is either supplied directly to the water distribution loop on the dialysis machines or is stored in an intermediate tank. In the case of storage in a tank, the ultraviolet devices contribute to the disinfection of the water before it is consumed in the respective dialysis machines. Reverse osmosis is also offered with the possibility of thermal disinfection of the loop and the reverse osmosis system to avoid the use of chemicals.