question for all you UV-C purifier users out there

I think "dilution" is just a way of saying that when you turn your bottle upside down and let some of it run out, hopefully the UV-treated water will wash away the untreated, residual water and baddies along the rim opening and bottle cap.

Is this good enough for most hikes in the US and Canada? Who really knows, but I tend to think so — considering that many don't even treat their water! But would I rely on the above in Ebola-infested Congo? Heck no.

My one reservation about UV treatment is that it works well only with clear (or near clear) water. No problems in alpine streams… but in the lower reaches, stream and river water can be completly churned up and brown, say, after a night's rainfall. And thus, your UV purifier can be performing very suboptimally just when you need it the most! Sure, you can let the water sit in a bucket, but that really defeats one big advantage of UV: it's quick treatment time.

You mentioned Nalgene, so in response since i sometimes use soft-sided, large mouth Nalgene Cantenes, here's my approach:

1. pre-filter your water through a bandana (one to several layers as req'd to get clear water.

2. dry threads and cap with another half a bandana or packtowel NOT used for pre-filtering, and not used for wiping mouth, eyes, etc.

3. treat w/UV-C per Mfr's instructions.

4. for drinking, i use a "sippy" straw arrangement that for the most part eliminates the concern that you raised about putting one's mouth on untreated water laden threads. your concern is NOT the reason i use a sippy top, but it just also happens to partially address your concern.

Could untreated water be forced from the threads into the Cantene when the sippy top is screwed onto it? Possibly a drop or two.

Would i still drink the water if i noticed such occurring? Yes.

Or, if you're still concerned that water from your cap threads entered your treated water, you could treat it again and the next time you put the cap on there may not be water in the Threads. Or, better yet, you could dry both the cap and container threads, then screw the cap on and off a couple of times and hopefully that would evacuate any water from the Threads and then treat the water.

Lose no sleep over this – i sure don't.

Technically, I'd call it irrigation, not dilution.

Other than having to lay in a good supply of CR123 cells, I can't think of a reason why the Aquastar wouldn't be a fine choice for the PCT. I've been using one for the last two seasons, and it's become my main treatment choice (in the Sierra Nevada). If you were confronted by some really dodgy water (e.g., in the California desert and Northern Calif-Southern Oregon) I suppose you could aways expose the bottle threading to the UV tube, and thoroughly irrigate the cap threading with treated water–for peace of mind. Most of the trail has very reliable water.

hey everyone, thanks for all your help.

so is it safe to say that if it is fairly dry there are no contaminants.

this is somthing i have always wondered… how dry does it have to be before the contaminants "die, or are washed away".

if it is moist but not wet, is it safe?

the thing is i have been hiking for years and drank from some pretty questionable sources and never had a problem, however, when i was in mexico it seemed like everyone got sick. i know that they are different contaminants but i just have to wonder how much precautions i really need to take. Jardine recommends not purifying at all. and i have heard some people say that they are not suseptable to giardia, of course they could just be really lucky.

i just want to ensure that i have a good hike and if i have to quit i dont want it to be because i have the poops.

thanks again.

will

Hi Will,

Can you expand on your question? Do you mean a dry container or a dry water source (creek bed, etc.)? "Moist" can certainly be contaminated–think of an old, wet kitchen sponge.

FWIW many bacteria and by their very nature, cysts such as giardia can survive extended dry periods, so a contaminated container should still be considered contaminated even after it's dry. Drying in sunlight has a sterilizing effect due to the UV, especially at altitude, but who can guess at how effective that might be in practice?

It's definitely the case that many exposed people aren't affected by giardia. I don't know that it's ever been demonstrated that such resistance can be developed, or if it's something we're born with or a sort of measure of our immune systems. I'll suggest ignoring Jardine on the topic of developing your resistance by exposing yourself to contaminated water.

It's arguable in any case that giardia and crypto shouldn't be the primary concern in Western mountains but rather, bacteria and perhaps viruses should be. I take my greatest precautions in areas of heavy stock use or obvious heavy human use, and am less strict with my regime in remote areas.

In sum, I think it's important to carry the system you're most comfortable using, then learn to judge each potential water supply. A decision to not treat should be based on being confident about the supply, and not because you hate filtering or the taste of your chemical treatment.

There are dozens of PCT journals on line. Read as many as you can to get a feel for filtering or using chemical treatments for four months. Pretty much everything has been tried on the trail. I've not seen many accounts of GI illnesses, and many of those are likely caused by questionable hygeine, not the water.