Filtration processes are a large cost component of pharmaceutical manufacture. The particle retention efficiency, particle capacity of the filter and the liquid flux all impact on product cost. A non woven electropositive filler media has been developed whose active component is an alumina (AlOOH) fiber two nanometers in diameter and having a surface area of 350-500 m7g. The nano fibers are dispersed throughout a cellulose/polymeric/ microglass fiber matrix resulting in a 2 micron pore size filter media. It has minimal pressure drop permitting sustainable water flow velocity greater than 1 cm/sec (3.6 L/ cm'/hr) at pressures of only 0.7 bar. A single layer of media retains greater than 99% of 0.03 µm latex spheres or 0.025 ^m size MS2 virus, justifying an Absolute rating of 0.03 microns. The media can be pleated to produce a high surface area cartridge suitable for higher flows or formed into a multilayer depth filter capable of filtering virus size particles to greater than 6 LRV (log retention value). Data are presented on the filtration characteristics of single layer pleated cartridges. Their filtration efficiency for AC fine road dust (average particle size = 1 µm) exceeds that of literature values for microglass, meltblown and membrane filters, with pore size ratings between 1 and 0.2 urn. It's dirt holding capacity is twenty times greater than 1 µm microglass media and almost 200 times that of 1 µm microporous membranes. It's clean water flux is typical of a 2 µm pore size and substantially greater than that of any of the above mentioned media.