Abstract: A water purification system has a longitudinal ultraviolet tube, an arrangement of helically-wound coils surrounding the tube and a filter. Water is exposed to ultraviolet energy before and after flowing through the filter. The filter, ultraviolet tube and helically wound coils are all arranged within a unitary housing adapted for kitchen countertop, sink backsplash or under wall cabinet mounting. The system is capable of operatng directly from a kitchen sink faucet. Connecting elements for the coils are specially designed to be leak-proof. A closed, reflective chamber surrounds the ultraviolet arrangement.