A method of making a filter cartridge, which method includes: (a) providing first and second filter media layers that each contain active particulate that is bonded together and that each comprise a perimeter; (b) stacking the filter media layers in a spaced apart relationship; and (c) securing a roll based housing sidewall to at least a portion of the perimeter of each filter media layer. The resulting filter cartridge is light in weight but has increased volume that provides an improved service life. The cartridge has a very good service life to weight ratio.