A water purification system includes an activated carbon filter and a reverse-osmosis (RO) filter. The activated carbon filter is typically formed with a central aperture that receives an upper portion of a central tube. The RO filter, which is positioned downstream from the carbon filter, may be formed around a perforated section of the central tube. The system further includes a head that is structured to receive a sump that contains the carbon and RO filters, as well as the central tube. An inlet formed in the head enables unpurified feed water to flow into the carbon filter. A first channel, which is defined by an annular surface formed in the carbon filter and an outer surface of the central tube, enables water to flow into the RO filter. A channel within the central tube enables water to flow from the RO filter, through the perforated sections of the central tube, and into an outlet formed within the head.