Abstract: A universal filter insert apparatus 10 for a water purifier includes a container insert 12 having substantially cylindrical or conical side walls 11 and an annular lip 17 at an upper portion thereof. A plurality of resilient sealing members 36 are stacked about the upper portion of the container. Each of the resilient sealing members includes (i) an internal sealing diameter 50 adapted to engage the container annular lip and (ii) a uniquely-shaped annular sealing flange 38 for engaging a filter receiving aperture 54 of a particular water purifier 52. At least one guide slot 22 extends along a portion of the bottom of the container insert. A granular filter medium is placed within the container insert and sealed therein with a container lid 30. The container lid has a plurality of apertures 34 sized to let water pass through and also includes a raised handle 32 for ease of insertion and removal of the universal filter insert.