ANYONE know the pore size of coffee filters??
i ask because i have an older model PUR filter--the Ultralight,
and i'm just about out of the paper filter discs and a web
search has come up blank..

The Ultralight is a great filter for mountain dayhikes, where Giardia is the main worry. It has saved me from lugging excess water for many a weary mile.

There's no way a coffee filter would work as a replacement, though many use it as a silt filter to extend the life of the main element.

I'll keep my eyes open for replacements. I hope they're still available.

The Web always has your answer:
http://geo.uri.edu/skydust/faqs.aspx and search the page for pore.

(Executive summary: Coffee filter pore sizes average about 100 microns.)

100 microns!! well it seemed like a good idea at the time-