bottle filters

What bottle are you using?

see: http://www.guyotdesigns.com/TapGuard

Of the three classes of baddies: viruses, bacteria, and protozoa cysts, the last one is also the biggest in size. Pretty much all backcountry filters — including the lighter, simpler, cheaper ones — can block out protozoa. Filters that can also block bacteria are more intricate and bulkier and heavier. The few that can also block or treat viruses are usually bigger and heavier still.

Chemicals kind of work just the opposite. The tiniest things (viruses and then bacteria) are the easiest and quickest to kill. It is protozoa, given their size and protective shells, that are the hardest to kill.

So in a long-winded way, I guess I am just surprised that you would ditch filter for chemicals because of protozoa! That's actually where filters outshine chemicals.

Aquamira, Katadyn, and others make various models of bottle filters that will handle both bacteria and protozoa.

Thanks Ben. I dropped Safe Water filter bottles in favor of Aqua Mira drops about 4 years ago to save weight, because Safe Water went out of business, and because a gear shop salesman convinced me that filter bottles wouldn't get rid of all the pathogens. My only concern with Aqua Mira is the taste. I force myself to hydrate enough maybe, but the aversive taste contributes to altitude-induced nausea, so I typically don't eat enough for the first three days of any hike over 8K. I'm considering another try with a Katadyn bottle or some other brand. The factors to weigh are flow rate, reliability, and how much of a risk there is from viruses which wouldn't be filtered in the Sierra where I usually go.

Thanks iamnot. The TapGuard looks like it could be an excellent solution to the problem. What has your experience been with this product?

Robert:

One big caveat of chlorine dioxide (Aqua Mira, Micropur, etc.) is treatment time. It’s a reasonable 15-20 minutes to treat against the tiny/easy stuff like viruses and bacteria. But to kill the larger protozoa that have protective shells — treatment time is 30 minutes all the way to 4 hours depending on water temp (the colder the longer)! Water up in the Sierras are usually on the cold side — meaning 2-4 hours!

I too hate the swimming pool chemical taste, and I use a combination method:

1. Treat with Micropur (or AquaMira) chlorine dioxide tablets — 1 tablet per quart or liter. Identical ingredients with A.M. liquid droplets, but tablets are more potent and there’s no fussing with counting droplets and no 5-minute pre-mixing time.

2. After 20 minutes (to treat just the bacteria/viruses) — drink water through AquaMira Frontier Pro filter. This filter weighs just 2 oz — and serves to block protozoa (who wants to wait 4 hours for chemicals to work?) — as well as clarify water and remove bad water taste — including chemical taste.

The combination “does it all” with much shorter wait time than chemicals alone, and a much ligher/compact filter than using filtering alone.

The Frontier Pro is very versatile — it can be used as an inline filter, a gravity-fed filter or screwed directly onto your water bottle. However, I would not use it by itself — its 3.0 micron pore size is too big — bigger than many bacteria out in the wilds.

sorry. I have no experience with this product. See REI for a review.

So Ben, is there much of a problem with flow rate with the Frontier filter?

I used mine hiking up Mt. Whitney. So no, no problems at all — thanks to its "generous" pore size. Just don't use the thing all by itself — as mentioned above.

Hi Robert

> My only concern with Aqua Mira is the taste.
You are not alone in finding the taste of chemicals awful.

But there is an alternative today: UV sterilisation. There are several products on the market with reviews at BPL. I like the Steripen Adventurer myself. No chemical, very short treqatment time, effective against viruses, bacteria and protozoa, in 90 seconds.

Cheers

I too hate the chlorine taste associated with AM. I have used the same system as Ben and it works rather well. Two thumbs up from me on that one!

Hi

I'm not too sure if this is worth a mention

http://www.bwtechnologies.com/aquapure_traveller.html

Apparently it is used by NATO when deployed in countries where water is unsafe to drink, and is the only filter bottle fully endorsed by the Hospital for Tropical Diseases London.

EDIT: How can I make my links work in this Forum?

Roger – Re: The Steripen Adventurer, am I correct in thinking that the pre-filter will not work on this model. I am considering the Journey for that reason, but am unsure which way to jump.

HTML Man to the rescue!

Click HERE for Aquapure Traveller bottle filter.

Darryl:

To create the above link, just type below:

<a href=”http://www.bwtechnologies.com/aquapure_traveller.html”>HERE</a&gt;

Benjamin

Thanks for your help

May also be worth looking at the bottles and/or in-line system from Aquagear

http://aquagearsurvivor.co.uk/products.html

Hi Darryl

I have not tried the pre-filter, but given the design of all the UV systems I don't think there is any interaction. So any sort of prefilter would work if it is compatible with your water bottle etc.

Not all the water I collect is safe to drink untreated, but I do usually manage to find water which looks OK at least. Some of it has a high level of tannin (so its brown), but it is still clear.

But then, I am not worried about large bits of stick and moss anyhow. I worry more about agro-chemicals. You can't filter them, and chemicals don't work on them either.

Cheers

Thanks to all. Lots of very useful information.