Abstract: A water filter cartridge includes a top end cap, a bottom end cap, a central support core and a pleated filter medium surrounding the central support core. The pleated filter medium includes glue beads formed on one or both of the outer surface and the inner surface of the pleated filter medium. The glue beads on the outer surface may be offset from the glue beads on the inner surface. The beads form ribs between the folds of adjacent pleats, which help maintain a rigid spacing between adjacent pleats of the filter medium and minimize the filter medium collapsing under water pressure when in use in a pool or spa filtering apparatus.