I found one of these at REI and thought I would give it a try. I haven't used it yet, but it seems very practical for cleaning that nasty water before you try to purify it. It folds up fairly small and is intended to pack under the fuel canister of most small camp stoves. The material is strong and seems like it would withstand quite a few uses.

GSI Outdoors Ultralight Java Drip

I always thought I would just use disposable coffee filters for that purpose but this looks promising.

I second the coffee filter method. I keep six small, (4-cup), cone-shaped filters folded in a plastic zip bag intended for daily medicine doses and it takes practically zero space in my EDC. If you let the filter dry-out before packing you can reuse it 2 or 3 times.

But with our disposables, even reusing, it is still a finite supply. This one is reusable over and over as long as it does not get ripped or otherwise compromised.

Agreed, but since I'm not planning to live indefinitely off my EDC or even BOB, my priorities are:

• Function
• Size
• Weight
• Availability
• Cost

If I have to live off the grid long enough to exhaust my supply of filters I would still have a bandanna and articles of clothing (either packed spares or what's on my body).

I also carry an Aquamira Frontier emergency drinking straw for about $10. It is said to be effective to 0.2 microns (the same as most pump filters), which would be good enough for Giardia, Cryptosporidium, (but not for Salmonella or E.Coli), and it's the size of a thick magic marker. There's a slightly-larger and more expensive ($20) Frontier Pro filter that has a replaceable pre-filter and can be screwed onto a narrow-mouth bottle, plugged into the hose of a hydration bladder, or made into gravity-feed water system (instructions on the Aquamria site or search on YouTube).

My son spent three weeks volunteering in the remote mountains of Ecuador this summer with only an old version Sawyer Filter Bottle, which incorporates a filter system into a water bottle with sip top. These are also rated for 0.2 microns, and he experienced no problems drinking from the local water sources (well, stream).

I think a bandanna is far more versatile for that.

oh, and that filter costs $9-10, plus $6 S&H. I can buy 500 disposable coffee filters at WalMart for $4.00. In a 2012 situation I could also break into any Dunkin Donuts or Starbucks to "borrow" more filters, and there seems to be no street corner in the country that doesn't have one or the other. ;^)

0.2 microns is actually sterilization grade (not including viruses) but even medical filters for cold sterilization are 0.2 microns. Thus if the micron size was correct, it would be fine for E coli and salmonella.

Eric

Mark,

Thanks for the info on the little straw type filter! I had seen things sort-of like that before, but without any data or reference.

My latest attempt at a lightweight water filter kit is a heavy duty, 4mil., ziplok type bag. In it is a BQ Survival Straw, 2 Survival Resources Aqua Pouches (1qt. ea.), the SR clear plastic coffee filter holder that folds flat, a couple of one-cup coffee filters and 8 Micropur MP1 purification tablets. Light and compact. YMMV