Water softening apparatus and installations; water filters, drinking water filters; water-filtering apparatus; water conduit installations; water purifying installations; water purifying apparatus and machines; water sterilizers; water supply installations; water distribution installations; water intake apparatus; filters (parts of household or industrial installations); disinfectant apparatus; purification installations for sewage; installations for water sterilisation; installations for water treatment; filter installations for removal of chlorine from water and decalcification of water, installations for disinfecting hot water/cold water, installations for hot water circulation disinfection, installations for treatment of ballast water; installations and facilities for water sterilisation