A water treatment unit with a housing having a housing interior and an oscillation unit mounted so as to oscillate in the housing interior. The oscillation unit can be set in oscillation by a coil through which an electrical alternating signal flows, wherein a water inlet and a water outlet are provided on the housing, and wherein a flow area is formed between the inner wall of the housing that delimits the housing interior and the oscillation unit, the flow area being designed such that water flowing from the water inlet to the water outlet flows around the oscillation unit.