Abstract: The invention relates to a device for adding a liquid or gaseous additive to tap water, comprising at least one additive container for the additive, at least one feed channel leading from the additive container to a tap water conduit located downstream of a controllable tap and at least one controllable closing valve placed in the channel. For the purpose of adding the additive to the water use can be made of a pressurized container. This pressure can be generated by a propellant gas already present in the container. It is also possible to make use of a pump incorporated in the device which can be driven in diverse ways. It is however recommended for the additive container to be coupled to a pump for pumping additive present in the interior of the additive container to the feed channel.