Abstract: A filter assembly for use with a bottle having a circular cross-section neck or open end includes a fine filtration media having a mean pore size of about 1-3 microns and capable of removing contaminants of 3-4 micron size and larger, and an inner filtration media disposed radially inward of the fine filtration media. The inner filtration media includes activated carbon, preferably a porous activated carbon/plastic matrix having a porosity of between about 10-150 microns. The outer housing contains the fine filtration media and the inner filtration media, and is dimensioned to pass through the neck or open end of the bottle. The fine filtration media preferably comprises sheets on opposite faces of a microfiber filter media formed of glass microfibers of varying cross-sectional diameters, with the fine filtration media in a pleated or accordion configuration. A filter assembly may also be provided having a spring pressed straw.