Abstract: A refrigerator cabinet water storage tank is oriented horizontally on the floor of the fresh food compartment and includes first and second side-by-side water storage chambers interconnected by a cross-over passage having a continuous taper which constantly increases the cross-sectional areas from the first chamber inlet to the second chamber outlet. The tank allows the water to enter from a domestic water source at a point lower than the exit tube outlet with the outlet arranged at the tank's highest point obviating the entrapment of air within the tank. The tank has an internal configuration providing maximum internal volume while fitting into a limited space. The water flow through the tank follows a serpentine U-shaped path to promote water turbulence which will provide maximum heat transfer.