Filter questions

[Jorel]

Two questions to my learned audience:

1. Has anyone used the new MSR filters? www.msrgear.com/watertreatment (http://www.msrgear.com/watertreatment)

They look very light, and the Autoflow, which you hang and let gravity do the work, intrigues me.

2. My wife, a chemistry teacher, swears no filter can keep out bacteria. Yet, all the manufacturers swear their product keeps out giardia, bacteria, and 99.99999% of other bacteria and crypto's.

Surely the manufacturers are not lying, right?

Thanks for your help.

Jorel

[Live the Journey]

Are you talking about the MSR Hyperflow? If so, you can read in the manuel that if the filter is exposed to temp.s below freezing it wrecks the paper filter and is officially un-usable (even though there's no visable damage)!! I was looking at that one, and once I read that I figured I'd better skip it...it'd be pretty cool otherwise, although I've heard it's not super easy to upkeep.

[take-a-knee]

Two questions to my learned audience:

1. Has anyone used the new MSR filters? www.msrgear.com/watertreatment (http://www.msrgear.com/watertreatment)

They look very light, and the Autoflow, which you hang and let gravity do the work, intrigues me.

2. My wife, a chemistry teacher, swears no filter can keep out bacteria. Yet, all the manufacturers swear their product keeps out giardia, bacteria, and 99.99999% of other bacteria and crypto's.

Surely the manufacturers are not lying, right?

Thanks for your help.

Jorel

Well. your chem teacher bride needs to review her college biology text. No filter will keep out viruses, at least not any filter practical for hikers. ALL of the quality filters have an absolute pore size of 0.2 or 0.3 microns (a micron in one millionth of a meter). That size is smaller than "99.9%" of bacteria. Viruses pathogenic to humans usually aren't present in enough quanity unless humans are living upstream. That's not to say they can't cause problems, just not usually from mountain springs/creeks. Protozoans are larger, 4-8 microns or larger(about the size of a human white blood cell), easier to filter, and a LOT more likely to trash your health. They are also harder to treat.

[Manwich]

99.9999999%, I'm sure i've had a cryptosporidium protozoan or two (or several thousand) that has squeaked past my filter, but the immense reduction of their numbers means my immune system would never be compromised by their weak armies.

Use the doohickey properly and you'll be skippy

[take-a-knee]

99.9999999%, I'm sure i've had a cryptosporidium protozoan or two (or several thousand) that has squeaked past my filter, but the immense reduction of their numbers means my immune system would never be compromised by their weak armies.

Use the doohickey properly and you'll be skippy

Good point, because of immune system variables, the number of organisms necessary to make a person sick (the infectious dose) varies a lot from person to person, and it varies as each person's health waxes and wanes. That's why some people, who chose their water sources carefully, don't treat and never get sick.