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Purifying water

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    • What is giardiasis?
      Giardiasis is a diarrheal illness caused by a microscopic parasite, Giardia intestinalis (also known as Giardia lamblia or Giardia duodenalis). Once an animal or person is infected with Giardia,
      the parasite lives in the intestine and is passed in feces. Because
      the parasite is protected by an outer shell, it can survive outside the
      body and in the environment for long periods of time (i.e., months).


      I grew up not knowing and drank all the time from free running streams. Later I found out... from watching freinds puke... oh well.

      Today I am allergic to Iodine both cat scan and little neck clams... and melon... During a trip with scouts they cleared a large quantity of water with iodine pills - I felt sick for three days. It took a day or two to figure out why... so I asked how they were purifying water... I grabbed a super filter and filtered the rest of the trip ... wow... won't let that happen again... so now I have Micropur Katadyn Sodium Cloride pills in the pack...
      Be wise enough to walk away from the nonsense around you! :thumbup:

    • WiseOldOwl wrote:


      I grew up not knowing and drank all the time from free running streams. Later I found out... from watching freinds puke... oh well.

      Today I am allergic to Iodine both cat scan and little neck clams... and melon... During a trip with scouts they cleared a large quantity of water with iodine pills - I felt sick for three days. It took a day or two to figure out why... so I asked how they were purifying water... I grabbed a super filter and filtered the rest of the trip ... wow... won't let that happen again... so now I have Micropur Katadyn Sodium Cloride pills in the pack...


      If they were puking, it was more likely viral. Giardia infects the colon mostly, the stomach hardly at all. Some of the bacterial infections go after the stomach.

      Iodine is ineffective against Giardia. Sodium chlorite/phosphoric acid (note chloriTe, not chloriDe: NaClO2, not NaCl) is indeed a decent choice. The Giardia cyst is also huge as microbes go, so filtration is even more effective against it. UV is also very effective, but I've seen too many malfunctions among people carrying Steripens.

      The commonest transmission vector for Giardia is hand-to-mouth, so wash your hands. Soap and water is very effective against Giardia, hand sanitizer not so much.

      And when life hands you a melon, you're dyslexic.
      I'm not lost. I know where I am. I'm right here.

    • AnotherKevin wrote:

      o huge as microbes go, so filtration is even more effective against it. UV is also very effective, but I've seen too many m


      A fellow named Roland Mueser published the book "Long Distance Hiking" back in the late 1990s. There's a chapter in it about water purification methods. His conclusion is surprising. He concludes that there's no provable statistical benefit to any of the purification methods in common use, and that most gastrointestinal illnesses among hikers are caused by careless sharing of food, poor cleanliness habits among hikers, and so on.

      I'm not sure if I'm in complete agreement, but his logic is sound. Based on my own experience: I never bothered with water filtration in the woods until 1989, when I acquired a serious case of the sh!ts after a weekend hike up and over Wildcat Mtn. Knock wood, there have been no repeats of that situation.

      FWIW, Mueser's book is still published and IMO still one of the best references on the subject, even if it's a bit dated as to gear.

    • rafe wrote:

      AnotherKevin wrote:

      o huge as microbes go, so filtration is even more effective against it. UV is also very effective, but I've seen too many m


      A fellow named Roland Mueser published the book "Long Distance Hiking" back in the late 1990s. There's a chapter in it about water purification methods. His conclusion is surprising. He concludes that there's no provable statistical benefit to any of the purification methods in common use, and that most gastrointestinal illnesses among hikers are caused by careless sharing of food, poor cleanliness habits among hikers, and so on.

      I'm not sure if I'm in complete agreement, but his logic is sound. Based on my own experience: I never bothered with water filtration in the woods until 1989, when I acquired a serious case of the sh!ts after a weekend hike up and over Wildcat Mtn. Knock wood, there have been no repeats of that situation.

      FWIW, Mueser's book is still published and IMO still one of the best references on the subject, even if it's a bit dated as to gear.


      The down off Wildcat E would scare the crap out of anyone.
      Non hikers are about a psi shy of a legal ball.

    • rafe wrote:

      A fellow named Roland Mueser published the book "Long Distance Hiking" back in the late 1990s. There's a chapter in it about water purification methods. His conclusion is surprising. He concludes that there's no provable statistical benefit to any of the purification methods in common use, and that most gastrointestinal illnesses among hikers are caused by careless sharing of food, poor cleanliness habits among hikers, and so on.

      I'm not sure if I'm in complete agreement, but his logic is sound. Based on my own experience: I never bothered with water filtration in the woods until 1989, when I acquired a serious case of the sh!ts after a weekend hike up and over Wildcat Mtn. Knock wood, there have been no repeats of that situation.


      It's hard to do a study with adequate statistical power to estimate the effect of water treatment. There's no good way to double-blind it (I suppose you could have placebo water filters or treatment chemicals), and it would be ethically questionable to solicit participation in a prospective study; I don't think my IRB would approve of having the control group not get adequate water treatment.

      I suspect that there is a major confounding of the effects of water treatment and of sanitation in general. I would expect that the water-treaters would also be more rigourous about sanitation in other respects: hand washing, proper cat holes, not having food handled by multiple people, and so on. As I said before, unwashed hands are by far a commoner vector for Giardia.

      I also suspect that studies depending on hikers' self-reporting are also questionable. It's surely plausible that people report better sanitation than they practice.

      In any case, I know on a fair number of my trips that I'm downstream of beavers, and I know about several nasties that are endemic in the beaver population around here. So I treat. And I still know that hand washing is much more important, so I do that too, whenever possible. I use sanitizer when it isn't. Half a loaf is better than none.
      I'm not lost. I know where I am. I'm right here.

    • AK, glad to see you say sanitizer. Some say you need hot water and soap, while I am sure that is better, it just is not as practical as a little plastic bottle I can keep it my pocket. I am not about boil a pot of water prior to every time nature calls.
      The road to glory cannot be followed with much baggage.
      Richard Ewell, CSA General

    • Astro wrote:

      AK, glad to see you say sanitizer. Some say you need hot water and soap, while I am sure that is better, it just is not as practical as a little plastic bottle I can keep it my pocket. I am not about boil a pot of water prior to every time nature calls.


      Even cold water and soap is more effective than sanitizer. But sanitizer is better than nothing.
      I'm not lost. I know where I am. I'm right here.

    • Astro wrote:

      How many of you have experience with a SteriPEN?

      Good/Bad?

      Would you recommend?

      Massdrop has the SteriPEN Classic 3 Purifier with Prefilter for $32.99
      I used one for 5 years before it gave up the ghost. I really liked it. Hard to beat a sawyer mini for the weight, ease of use and price. I'm a terrible gear head and might buy one for 32.99.
      bacon can solve most any problem.

    • For Idaho I'm going with Sawer Mini w/ frequent replcements & back up. Why? Cattle!.

      East coast vs west coast/rockies varies greatly. Lots of National Foress &even some wilderness areas still allow some livestock grazing. I've come up to my only water source in 20+ miles to see cattle grazing, pooping & pissing in it! Tat time I was saved by a local. He drove us about 1.5 miles to his house with a lawn & pond & well water. He was off to work but said we ould relax & camp there. While we enjoiyed this oasis for several hours we decided to push on during a full moon through the desert since nextwater was 26 miles ahed & not sure what we would find there!