Apparatus for filtering water; apparatus for supplying water; apparatus for water supply; devices for the separation of impurities from water (purification); filtering installations for water; installations for purifying water; installations for the recycling (purification) of waste water; installations for the treatment (clarifying) of water; installations for water supply; machines for purifying water; pressurised water installations; ultraviolet water sterilisation units; waste water treatment apparatus; water filtration apparatus; water purification installations; water treatment apparatus; water treatment units