Homemade ultralight one micron backpacking water filter

Well, I don’t want to mix the activated charcoal and the water before passing it through the micron filter bag but let it flow through the charcoal after it has passed the micron filter. Just a small PET-pipe filled with charcoal and plugged at both ends with synthetic cotton wool, through this pipe flows the micron filtered water.

I wonder if you could put a tablespoon of powdered charcoal into the coffee filter (prefilter)? This would probably adsorb a lot of chemical junk in the water but would probably pass through the coffee filter and ultimately plug up the 1 micron job. How would you do the charcoal thing…in a light and cheap fashion?

The sun thing will work—the heat and ultraviolet light will sterilize water in the tropics, but you can’t hike and do this…you have to sit and watch your water stand there in in sun for a full day!

The iodine solutions won’t kill the large cysts of the echinococcus tapeworm found on Isle Royal and in a few other places. I tried to find out if the steripen worked against these 42 micron cysts and was not able to do so.

Sure 1/2 is smaller than 1 micron. What I meant was that I don’t use 1 micron to filter out bacteria…ONLY PARASITES. As you go to smaller filter sizes, though, you begin to get the benefit of some bacterial removal, too, but I wouldn’t rely on it for this purpose. I’d use polarpure or potable aqua to kill the bacteria after I’d filtered out the parasites.

Great–that should filter out even some of the larger bacteria, but I wouldn’t rely on it for that purpose. E. Coli are 1 x 0.25 microns.

Right..you can’t be too careful The lightest thing would be to pop in a couple of Potable Aqua pills per quart. But the pills won’t kill any more echinococcus.

I’d say 90% at best…I kind of remember that the industrial standard was 80% filtration for 1 micron particles. Since the smallest parasites that you have to worry about are 5 to 7 microns, eg giardia or cryptosporidium, and since the 2D area of a 5 micron particle is 25 times the area of a 1 micron hole, I’d guess you’d get a 99% or more hold back. Really, I’m only worried about getting cysts in the brain, and since those 42 micron parasites have 1600 plus sq. microns area, I feel safe.

I agree: Boiling works best, but fuel and stoves can be heavy–I figure one ounce of propane/butane per quart of H20 but can get by with 1/2 oz if the weather is warm and the wind is still. Polar Pure is also great but I’ve had one of those glass bottles break in my pack…not good! Also, the Polar Pure doesn’t kill the hydatid cyst tapeworm eggs found on Isle Royale and other places…so you have to boil or use some kind of filter up there.

I think you could use the uncut filter bag (from which this cone filter was made) as a millbank type bag. It would be better than a canvas millbank because it would filter out parasites…if not bacteria. It would be worse because it would probably be slower and plug up sooner. Still, you could wash or even boil the 1 micron filter bag and then reuse it…at least a few times, I’d guess..

A millbank bag. Used by the british military to filter water.

How does this compare to the millbank