Abstract: A home water purifier is described, which includes a column of beads of ion exchange material and a column of grains of activated charcoal, which is of low cost construction. The filter includes a housing (26, FIG. 2) with a vertically-extending chamber having an air outlet at the top, a water inlet (46) at the middle, and a water outlet at the bottom. A mass (60) of activated charcoal grains lies in the lower portion of the chamber to remove impurities, and a mass (56) of ion exchange beads lies above the charcoal but below the water inlet to remove heavy metals. An air passage (64) formed along the upper portion of the chamber holds a retainer (66) of open cell foam material that prevents loss of the filtering material if the filter is turned upside-down during transport.