A filter block may comprise activated carbon filter particles without metallic biocides. The activated carbon filter particles may have a median particle size of less than or equal to about 90 microns and having a particle span of less than or equal to about 1.7. The filter block may have a permeability of greater than about 3.0×10−9 cm2 and a Filter Viruses Log Removal of greater than about 2 logs. A portion of the activated carbon filter particles may be coated with a cationic polymer. Another filter block may comprise mesoporous activated carbon filter particles without metallic biocides, wherein the mesoporous activated carbon filter particles may have a median particle size of less than or equal to about 104 μm and a particle span of less than or equal to about 2.05, and wherein at least a portion of the filter particles may be coated with a cationic polymer. The filter block may have a permeability of greater than about 2.0×10−9 cm2 and a Filter Viruses Log Removal of greater than about 2 logs.