System disinfection describes a hygiene measure in the fresh water system of mobile vehicles (motor homes, yachts, caravans, food trucks, etc.). Due to the storage of water in the fresh water tank, the associated increase in temperature of the fresh water and available bioavailable nutrients, microorganisms, but also pathogens, can multiply rapidly. Furthermore, there is always the risk of retrograde contamination. A settlement of bacteria in parts of the fresh water system with little or no flow (see also stagnant water) is also inevitable. To minimize the settlement and multiplication of microorganisms, system disinfection should be carried out at regular intervals (depending on user behavior) from a hygienic/microbiological point of view.