I'm sure this is a stupid question,and Montero and scafool's comments cause me to think of it. Particularly the former's. Given that filtration in and of itself isn't enough and purification still must follow, could it be argued that this filtration process was TOO cumbersome? My thinking is, and obviously I've never had to do it, is that if in fact a coffee filter works to 20 microns perhaps a filter of sand and a coffee filter might have accomplished the same filtering of larger stuff since all the purification still had to follow anyway? That probably ain't too smart, or someone else would have said so. Just curious.