An automatic dispensing apparatus for dispensing liquid at discrete time intervals, including a reservoir for containing a dispensable liquid, a dispensing tube positioned within the reservoir and in fluid communication with the liquid within the reservoir, and a dome at least partially enclosing the dispensing tube. The improved design has only two dispenser components, and use of the dome eliminates any trapping of air bubbles which can delay or prevent dispensing. A method for using the dispensing apparatus also forms a part of the present invention.