Abstract: An apparatus for purifying and disinfecting water including a tubular housing having a rear inlet end and a front outlet end, a disinfection stage and an absorption stage containing activated charcoal being provided in the housing between the rear inlet end and the front outlet end. Each of the disinfection stage and the absorption stage have a front end and a rear end at which a respective perforated cylindrical insert is arranged, the cylindrical inserts having an outside diameter which corresponds substantially to the inside diameter of the housing. The inserts at the front and the rear end of the disinfection stage and the insert at the front end of the absorption stage are arranged to be stationary and the insert at the rear end of the absorption stage is arranged to be axially displaceable.