I have been using Tincture of iodine 2% when I go backpacking and have had great success with it. I haven't gotten sick and I usually can't taste the iodine in the water. I've been hearing a lot of people talk about aquamira drops lately. I am curious what people think about the two and which they prefer.

There have been several studies on the efficacy of various water treatment chemicals including iodine and household bleach. Most chemicals work well on bacteria and viruses but few are truly effective against encysted Protozoa such as giardia and cryptosporidium. Iodine and bleach are not among those that are reliably effective against cysts. Chlorine dioxide compounds such as Micropur are effective against cysts but only given about four hours contact. Cysts are best removed by filtration. For really cruddy water I will filter first and then add ClO2 as Aquamira or Micropur.

Iodine has been shown to cause a number of health issues if used in excessive amounts and what is excessive is highly variable. When I was in the Army I drank a lot of iodine-treated water. I was OK for short periods but after a month or so I would suffer a low grade general malaise that I attributed to iodine. Now, I will use it only if there is no alternative.

What Pika said. The CDC used to list iodine as the treatment of choice... That's no longer the case.

I take Micropur tablets to back up a very light filter.

In regard to iodine, I used iodine exclusively during 13 treks (from 3 to 29 days) over a 2 year period. Probably drinking 2-3 liters a day at minimum. (4 drops iodine per liter) I was treating very questionable water (in a developing country with poor sanitation). I got stomach sickness once while on trek, although I attribute that particular sickness to some super-sketch food, not the water. So, that is my experience. Now I use a water filter just for the difference in taste.

After a few weeks of using iodine to disinfect my water (only on weekends), I broke out in a really horrible all-over rash with deep lesions (lichen planus), that left permanent scars. I was so sensitized to iodine that I still cannot eat seafood or anything made with iodized salt, which causes lots of problems, not just socially (since most people and restaurants cook with iodized salt) but also medically.

Iodine treatment for water is definitely contraindicated for pregnant women and children, which should tell you something. It's also a no-no for anyone who may have thyroid issues.

Plus iodine has been shown to be ineffective against cryptosporidium, which is becoming an increasing problem in many areas.

The CDC recommends iodine for water purification only for brief emergency use.

What about the aquamira drops?

I'll offer that you really want to get to know your water sources if possible.

Around here I don't treat my water very often. I use a Britta charcoal filter if it isn't pristine, and maybe boil it if I have any reason to suspect it's tainted.

I've also began to take a "Lifestraw" with me in case boiling isn't a good option. The Lifestraw is great for drinking water, it will remove darn near anything bad for you, and the charcoal filter plus boiling will purify any water you come across. That's a pretty light and inexpensive method.

The Chlorine Dioxide tablets are small and light enough to have a few on hand in my med kit, but right now I don't have any and I've never used them. They'er expensive, and I just don't need them here.

The real problem I have with Chlorine Dioxide is that it will certainly kill the good bacteria in your gut too, and that can increase your chances of getting sick. That's often the root cause of getting sick from untreated water.

In the past I've used iodine too, but after it set the required time I filtered it with a Britta Charcoal filter. That makes a big difference in how clear the water is and it removes the taste of the iodine. There may be some left over chemicals in the water doing that but I never got sick. I'd do the same if I were using the Chlorine Dioxide. It won't remove the chlorine, but it will reduce the taste of it by a lot so it does remove a lot of something.

If I knew I always had to use a treatment I'd buy a Sawyer Squeeze filter instead of what I'm using now, but I wouldn't use chemicals as my primary method. They're for emergencies only.

Aquamira Liquid is not intended for our needs as backpackers. The only liquid solution I know of that is a purifier is what is made by the MSR Miox.

I don’t want backpackers out there using the liquid and having a false sense of security. A certain concentration level and contact time is needed. A weak mixture of chlorine dioxide just isn’t going to kill the nasties and that is what AquaMira liquid is.

The chlorine dioxide tablets are good. Just ensure that they say they can kill all the nasties. If they are good, they will say that a contact time of up to four hours is required.

Aquamira’s website has this to say about its tablets: “When used as directed, Aquamira Water Purifier Tablets meet the EPA guidelines for Microbiological Water Purifiers making it the safest solution on the market. Great for weekend hiking, camping, hunting, or fishing trips.” Nothing of the sort is stated for the liquid.

I was always hearing before from others that it was just a bureaucratic issue about EPA registering and that it didn’t mean much. I always thought that if Aquamira wasn’t willing to have proper laboratory studies to get it EPA registered, then they didn’t care enough for my needs. Now that they have gotten their tablets registered, a different picture seems to be painted. The drops don’t meet EPA guidelines for killing all the nasties and, therefore, don’t qualify as “the safest solution on the market” as they promote for their tablets.

I am curious about your statement as many municipal water treatment plants use chlorine dioxide.

For sure, Chlorine dioxide is toxic, that's why it is used to treat water. That treatment is probably a necessary evil as things stand now, but that doesn't mean it's the optimal solution, hence all the filtration systems you can buy for your home to filter that out.

Gut bugs play a huge role in maintaing health, so it behooves us all to keep them healthy, and minimizing their exposure to Chlorine dioxide for health reasons seems obvious to me.

Still, when chlorine dioxide kills a bug in water it converts to chlorite, which is also toxic. So while you won't get sick from the bug, you do ingest some nasty stuff in the form of a very powerful oxidant. At the very least I would want to take a dose of antioxidants with it. A packet of emergen-C would be good. I take those everyday anyway, and bring extra when I'm backpacking, but that won't protect or replace your good gut bugs. Drinking good, untreated water might though.

I have to add a bit...

The good bacteria in your stomach is like a first line of defense against any bad bugs you might ingest. You need to keep them healthy. Taking probiotics is one way, eating yogurt with live cultures, kimchi, sauerkraut, raw fruits and veggies, etc.

What kills those good bugs are things like antibiotics, chlorine, and probably soft drinks that contain sulfuric acid, like Coke. Antibiotics are the worst, and the stronger they are the harder they are on your good stomach bugs.

So, if you've taken a round of antibiotics, then head off backpacking and are only drinking water treated with Chlorine dioxide or iodine you could be very susceptible to getting nailed by those very few nasty bugs, rather from water or personal hygiene or any other source, whereas with a healthy gut you'd never even notice you got any, your gut would fight them off with ease.

That four hour time can be more than is needed. It's for dirty, cold water.

http://www.katadyn.com/usen/technical-support/micropur-support/

Of course, it doesn't say whether clean, warm water should have the 30 minute or 4 hour treatment time to treat cysts....

The wait time is why thru hikers often get the Aqua Mira Frontier Pro - which is NOT suitable to rely on it for anything but filtering the largest critters out - but, cysts are quite large by comparison to bacteria. So a pass through the Frontier Pro followed by 30 minutes with chlorine dioxide does the trick.

That is true. But my point was to ensure that the package says that a contact time of up to four hours is required. In very few cases, however, would that much time be needed. I would usually treat water at night and it would definitely be ready in the morning.

Except that the Aqua Mira Frontier Pro filter is 3.0 microns. I had to do a lot of research to find that out because (3 years ago) Aqua Mira did not disclose the filter diameter. (I just checked their web page and they still don't!) The CDC recommends a 1.0 micron filter for protozoa (giardia and crypto).

WyOutdoors,

I have used both, each for six months at a time. I used the iodine crystals in the refillable bottle. I think it was called Polar Pure or something like that. Haven't seen it on the market for some time. I now use Aqua Mira liquid (we get it as Pristine).

I had no problems with either, but prefer the chlorine dioxide. While I did not mind the taste of iodine, it's nice to not have it, and I'm convinced the chlorine dioxide does a somewhat better job.

But for me, Billstephenson makes the most important point: learn to evaluate water sources. Even on the AT I was able to use water straight fairly often and never suffered for it. But remember that there can always be something you'd rather not know about just around the bend out of sight. If I have any question in my mind, I treat (sometimes with a double dose and for several hours).

best, jcp

Lots of input already. I'll add my two cents:

Chemical treatment

• Iodine--works against bacteria and viruses, not against cysts.
• Chlorine dioxide (ClO2)--several log more effective than iodine against bacteria, effective against giardia in 30 minutes, 4 hours for crypto.
• Miox (mixed oxidizers)--brews up a mix of free chlorine, ClO2, hypochlorous acid and trace amounts of other oxidizers. Same general effectiveness as ClO2, in my experience tastes rather stronger (probably varies depending on source water and one's palate sensitivity).
• Household bleach (sodium hypochlorite)--A little better than iodine against cysts, less effective against bacteria and viruses than ClO2. Basically free.

I don't like chemical treatments for aesthetic (taste and odor) reasons and their spotty efficacy. ClO2 tablets are the simplest and probably affect water taste the least, so that's my standard fallback in case my primary method fails, or I'm day hiking. Over the long haul, it's a very expensive option (the two-part liquids are much cheaper than the tablets). All the tablets are made by the same company but are packaged by a few for retail sale.

I will never rely on iodine or household bleach, period; virtually every other chemical option has much better results. Miox is fun to fiddle with, but tastes like a salty swimming pool.

UV

Broadly effective against viruses, bacteria, cysts. Affected by turbidity and temperature (device design can counteract the temperature effect to some extent). Instant (stir and drink) and does not affect taste. It's fine for soloing, but IMHO too fiddly for groups (far too much scooping, stirring and pouring). Batteries are an ongoing cost and don't be tempted by cheap offbrand CR123s.

Filtration

The most common tool. I've used many, many over the years and so long as I'm not fixated on viruses (I'm not) does what I need w/o affecting taste. After years of pumps I've converted to gravity filtration. Because I'm lazy. I won't go into comparatives among brands and models, I've settled on the Sawyer system. It flat works and with adequate backflushing is a lifetime purchase. They do make a virus-level filter with a rather lower flow rate. If I were headed to the tropics I'd get that.

Drink up!

Are aquamira drops sold at local store or mist they be purchased offline?

I've bought it over the counter in Washington state, but not in California. I don't think they wanted to pay for the Cal/EPA testing. The Pristine version might also be available, they're in Vancouver, CA. Same stuff.

Cheers,

Why does this canard continue to be perpetuated. As I stated above, I was always hearing before from others that it was just a bureaucratic issue about EPA registering and that it didn’t mean much. So why did did they then obtain registration for their tablets, but not the drops? The drops don’t meet EPA guidelines for killing all the nasties and, therefore, don’t qualify as “the safest solution on the market” as they promote for their tablets.

Aquamira Liquid is not intended for our needs as backpackers. I don’t want backpackers out there using the liquid and having a false sense of security. A certain concentration level and contact time is needed. A weak mixture of chlorine dioxide just isn’t going to kill the nasties and that is what AquaMira liquid is.

Quite a bold statement that I'm sure you can verify with a cite, yes?

Aquamira crypto test for US-EPA certification

Not bold, just truthful. All one has to do is look at the Aquamira site. According to their site, the tablets qualify as “the safest solution on the market”. No such claim is made for the drops and no EPA registration is listed (unlike the tablets). What is clear is that the drops have not been registered with the EPA (unlike the tablets) and, as such, their efficacy for killing the nasties to EPA requirements is unproven. As such, why trust an unproven product that is not marketed for backpackers' uses? That is not a risk that I am willing to take given the plethora of reasonable alternatives available. I don't mind people buying the liquid, but only as long as their eyes are wide open to its limitations.

As for the 13 year old study, I don't think it stands for the proposition proffered. That was done with respect to Carnebon 200 and Aspetrol separately. Are either of those actually the mixed liquid? Secondly, you may want to review the conclusions as both of those failed in killing cysts in half of the tests. Also note, that was only with respect to cysts and not other nasties. The report says it is to be submitted to both the EPA and CAL EPA. So why wasn't registration successful?

So you missed this, yes?

And for a comparison against iodine and Miox against bacterial biofilms, this.

EFFICACY OF CHEMICAL WATER TREATMENT TECHNOLOGIES IN THE BACKCOUNTRY

Aquamira and Pristine liquid treatments work, and can be used with confidence. I prefer filtration, myself.

Cheers,

No, I did not miss it, but it is irrelevant to the discussion as related to backpackers. There is a dramatic difference between an “EPA Registered Water Treatment” and an “EPA Registered Purifier”.

As Aquamira states, “When used as directed, Aquamira Water Purifier Tablets meet the EPA guidelines for Microbiological Water Purifiers making it the safest solution on the market.” But for the liquid, Aquamira makes the following claim, “Aquamira Water Treatment treats drinking water using chlorine dioxide to kill bacteria, control the build up of slime and improve the taste of stored water.” See the difference?

As for your other link, perhaps a review of some quotes would be helpful to put the scope of the study in context:



Interestingly, you didn't address any issues I raised about the 13-year old study you previously cited as support.

HYOH, but to state unequivocally that, "Aquamira and Pristine liquid treatments work, and can be used with confidence." provides a false sense of security for the situations backpackers face.

That is incorrect. The drops and tablets have the same concentration of ClO2 if used as directed. There were legal reasons for the EPA registration inconsistencies. Suggested reading

Thanks for the information as it is more illuminating on the subject. However, the link does raise a few concerns.

1. The information from the link is that "the initial claims from the bulk supplier for Aquamira Water Treatment were 'bacteria, taste and odor', and all testing was done in potable water. . . . " So that pretty definitively states how far Aquamira can go in making its claims, which is not far enough for backpackers.

2. The following statements are made:

(a) "The reason that the instructions call for a reaction wait time of 5 minutes is so that the mixture can be added to the water at the peak of ClO2 production. If a person adds the mixture too early or late, the final concentration of ClO2 in the water can be significantly less than the required 4ppm." That gives me some pause for concern as I am unsure how many of us pull out our stopwatches to ensure that the mixed solution is dumped at the exact proper time.

(b) "We recommend poring [sic] some of the treated water into the mixing cup and then pouring that back into the container of water to flush out any residual material from the mixing cup." How many do this religiously?

(c) "Mixing in a windy area or at higher temperatures can add to this potential loss of ClO2." So if it is hot or windy, proper concentration may never be reached.

3. Finally, "Recently Aquamira procured the EPA registration for the base chemical from the supplier and we are now in the process of submitting our own label with appropriate claims to the EPA. This is a lengthy process, and requires every claim to be backed up with test data. Some of the data was not available from the bulk supplier and must be supplied by Aquamira. We expect this process to take up to a year from now to complete." It has been over 2-1/3 years since Aquamira's prediction as to when the process would be complete, which is well over twice the amount of time at the longest. Yet still no EPA registration. Take from that what you will, but at this point I still stand behind my opinion that Aquamira Liquid is not intended for our needs as backpackers. After all, Aquamira doesn't state that it is.

Kinda late to this party....But...

In the interest of this discussion, and note that I have NOT read ANY of the link,



That statement in itself suggests that if your backpacking water issue is bacteria, you would be fine as most of us would select potential "potable water" sources to drink from. I take this statement more as an indication that the water chemistry is within acceptable drinking water standards and isn't abnormally high in one or another chemical component such as say Ca and SO4, or maybe water percolating through mine tailings. Acceptable as treatment is assuming that these tests showed Aquamira was effective at treating bacteria of course.

Interesting there is no mention of virus or Protozoa treatment testing.

This discussion is interesting and it was informative to read the responses. I'll have to check out the links later. Personally, I am not inclined to use any chemical additives in my drinking water. But I am curious about all these different methods of water purification. I am also curious, NDSOL, if not developed for backpacking use (and/or to make money with), what do you think this stuff was originally developed for? Third world water treatment for bacteria?

I would interpret the statement, "all testing was done in potable water" as just that. The water that was used to do the testing was drinkable, which dovetails into your question about the uses therefor.

Potable water exposed to air (and everything in the air) does not stay potable after a period of time (dependent on numerous factors). Aquamira liquid is labeled to keep that period of time greatly extended. So if you have stored water for emergency purposes or perhaps in your RV water tank, then the Aquamira liquid will keep it still potable by killing bacteria. Similarly, if you have a animal watering trough that is filled by a well that delivers potable water, then this should help keep the water safe and free from slime caused by bacteria.

By analogy, think of the liquid you buy to add to gasoline to ensure that the gasoline will not break down and will still be good next year when you pull your lawnmower out after the winter.

Anecdotally, I've not yet heard of any backpacker using the AM drops having any illness issues and FAR more use the drops than tablets because they're less expensive. I'm sure they don't follow the directions really precisely either. Some even premix a day's batch worth to save time, especially if in a group setting. However, I also think the danger of infection in the wilderness is overblown, which is why you rarely hear about people getting sick.

I agree that it is probably well overblown (especially in the areas where I generally backpack). What is more important is practicing good hygiene for which hand sanitizer plays a crucial part IMHO.

Totally agree that good hygiene is crucial. In my last solo trip, I didn't carry any treatment method at all. But I was confident as to what quality water I was going to get.


Ndsol, interesting take on what Aquamira was developed for. The line of reasoning makes sense in as far as what I have read. I'll have to see if I can use it for my rainwater collection system (off my roof).

Just as an aside, potable water = drinking water. Pretty simple really. But in the United States, this does indicate to me that it must be potable water as accepted in the US. These are basically chemical guidelines, including a maximum total dissolved solids (TDS). There would still be a broad range of chemistry accepted, and would depend upon the source. Certain water chemistry could potentially interfere with the intended chemical process rendering the treatment ineffective. Anyway, this is just part of the thought process that goes through my head when looking at this stuff.

I think it's worth noting in this thread that water in a clear plastic (PET) container left in the sun for 5 hours at 86º F is an effective and recommended treatment. When used with a charcoal filter you'll end up with as good of water as you'll get just about anywhere. While this may not always be an optimal method for backpacking there are certainly times when it can be.

Solar Disinfection

Here is the collected thoughts I have on the topic:

Giardia is out there. When, where and how much is the question that will never be answered - there is no test we can do to verify, so the only completely safe thing to do is treat ALL WATER.

How do I know it is out there? I keep running into people who have had it - not just "got sick" but "went to a doctor, verified the diagnosis and had to have a bunch of antibiotics because it was giardia." This includes water rescue team members (who do not backpack, and therefore there is no "hygiene issue" to blame) who have been treated 2-3 times apiece for giardia, thanks to white water kayakers who go hike in miles and get into some mid elevation stream (Cherry Creek, the Kings River backcountry, and Dinkey Creek are but three central Sierra locations where they do this kind of thing, and sometimes things go wrong and they die - this happened just a couple years ago in Dinkey).

Do I know where it is? Nope. But I go up there 3 - 10 days per month. Odds are in my favor of exposure. At some point (don't know when, don't know where) conditions will be such that the little buggers may just hit critical mass just as I arrive at the stream to take a drink. So I'll keep ignoring comments about "overblown" and keep filtering, thanks all the same.

Someone who spins the wheel twice a year (the majority of the population I'd guess) and doesn't get sick has no impact on my belief that it's out there, because they don't go often enough to have that much of a risk. It's like fishing. If you stand in one place long enough, pitch the same lure every few minutes, eventually some dumb fish will swim by and bite - it doesn't mean the fishing in that spot is good, or that you're a good fisherman, or there are a lot of fish in the water, it just means you spun the roulette wheel often enough to get lucky. That's why rangers will tell you to treat the water. If enough tourists head out on enough trails to enough waterways.... some fraction of them will be unlucky, and some smaller fraction of them will have a good attorney.

I will always do my best to be safe. I'm the only one I have to take care of me. Depending on some decade old study or some edumacated hunch someone has is not good enough.

As I recently told another backpacker in a fairly untrammeled Oregon wilderness area that's at least 350 miles from any major metro area, if it were a question of getting dehydrated for lack of a filter or treatment, due to some accident or oversight, I wouldn't hesitate to drink the water there straight out of the stream, untreated, because the chance of getting a waterborne illness was extremely remote, whereas dehydration is much more immediate and life-threatening -- however, I always do bring a filter and I always use it, just because giardia is a nasty, serious disease I would not wish on anyone.

Well, I'd counter that you're using treatment as a first line of defense. I believe it should be used when there is a high degree of known personal risk.

One of the ways a body build immunities is by exposure to small amounts of the substance that cause an illness. There are many, many, people who are immune to Giardia variations that thrive where they live. ( one of many credible sources )

That is what I meant when I said drinking untreated water may help build your immunity to Giardia. Getting taken down hard with Giardia is almost always a sure sign of a weakened immune system.

There are many ways to strengthen your immune system that are well documented. Also well documented are many ways to weaken your immune system. Using chemical water treatments is a surefire way to reduce or stop your natural defenses against giardia, so is taking antibiotics.

I choose to try and keep my immune system strong with a selective diet, exercise, and if my diet is lacking, nutritional supplements made for that purpose, and by avoiding antibiotics and toxic chemicals like Chlorine Dioxide, which are known to weaken the immune system. I have never gotten sick drinking untreated water from clear running wilderness streams.

It's important to note that most Giardia infections are transmitted human to human, not by drinking water. Your hiking partner can be immune and still be a carrier and if you don't sanitize them too you're still at risk no matter how well you filtered your water.

In short, I'd rather work on building an immunity than preventing exposure.

You might call all that "some edumacated hunch", but there is well documented scientific research to back it all up and there are risks involved in ignoring it.

What do you do to boost your immunity to e coli? Cryptosporidium? any other bacterial infection?

e coli is another semi-common problem that appears in waterways. Particularly along the John Muir Freeway, it's been detected in rivers in the parks.

I'm late to the party (nothing authoritative to contribute), but now that we're in the "summing up/what's done in practice?" stage of the thread, I'll chime in.

I agree that building immunity is important, and maybe the best defense (which is why I don't make use of any of the alcohol dispensers that are at the entry to every public building.) While ole Dan'l Boone had better quality water to drink, mostly, he probably also had a sturdier immune system from prolonged exposure. (Of course, no one's going to carve "D. Boon had diarrhea here" on a tree, so we may not have all the evidence available.)

In practice, I also tend to take the "belt and suspenders" approach to water purification: choose reasonably safe sources, but still purify. At 4 ounces and minimal effort (gravity filter), it's pretty cheap insurance.

Like someone else said, reasonableness and situation also play a role. When I've seen it bubbling up out of the ground, 2500 feet above and 20 miles away from the nearest village or farm, I will drink without purifying, maybe (I'm not immune to that temptation), but often I'll even purify then. And, given the choice between dehydration and drinking unpurified water, I'll drink the water.

A strong immune system is an excellent thing to cultivate, but a strong immune system is not a foolproof answer. Any immune system can be overwhelmed by a large enough exposure to a disease organism.

To my way of thinking, drinking untreated water is a crapshoot. All wild water will contain an unknown number of organisms of unknown type. The risk that the type and number of organisms in the water you are ingesting will be sufficient to make you sick can be guessed from observable clues, like turbidity, odor, proximity to grazing, etc, but unless you have a laboratory with you, you are only making guesses.

I happen to prefer filters because I would rather remove things from my water than add chemicals to it. For me, the choice is bringing the filter and using it or doing nothing at all. Filtering may not be 100% effective, but it will certainly reduce the numbers of organisms in my water. I let my immune system deal with any organisms that escape the filter. This seems like the proper utilization of my immune system, rather than having it bear the brunt of anything and everything that wild water might contain.

How does this work out for me? So far, so good.

Maybe someone or he did and it just hasn't been discovered!!!

Or the thought better of it after he did, and went back with his axe to erase the evidence?

In short, you build your immune system up with probiotics and antioxidants. Here's a more detailed description of how your body does this for you, given a chance:

Immunity to Enterotoxigenic Escherichia coli

"Seventeen students and other community volunteers were given 106 or 108 organisms of E. coli B7A (O148:H28), which produces heat-labile and heat-stable enterotoxins. Ten individuals developed diarrheal illness closely resembling natural travelers diarrhea; of these ten, rises in titer of serum antitoxin and anti-O antibody occurred in eight (80%).

Eight of the volunteers who developed diarrhea in the first test agreed to undergo rechallenge 9 weeks later with 108 B7A organisms. Only one of these eight “veterans” developed diarrhea versus seven of twelve controls given the same challenge (P = 0.05)."

The mechanism by which Cryptosporidium causes diarrhea is still poorly understood, and so is the immune system's response to it, but for certain the risks of exposure is much higher for municipal water supplies than clear running streams in a wilderness area. It's also certain that your body can fight off small exposures if your immune system is strong. It's very unlikely you'll be overexposed when drinking from a clear running stream. Still water (a pond or pool) would increase that risk a lot if the cyst were present (and as you said, there is no fast and easy test for them).

I already pointed out that for Giardia human to human exposure is (by far) the most common way to get sick from it. The next most common is from dirt.

All this is not to diminish the need to know when you should treat your water, or knowing to err on the side of caution if you don't. It is to focus on the need to know how to evaluate a water source and to try and put the risks into perspective.

The facts are that we are most likely to get Giardia from our friends and after that the dirt we're walking on, and we're most likely to get Cryptosporidium from our kitchen faucet, and we're most afraid of getting them from water in the wilderness.

I understand the first three, it's that last one that trips me up.

Bill raises excellent points. In one, he refers to probiotics. It wasn't too long ago when all bacteria was considered "bad". As we learn more, we are finding that all micro-organisms aren't bad and some are not only beneficial but necessary. Our species evolved to live in the environment including all the micro-organisms. Since we are already discovering some of the beneficial micro-organisms, it isn't a giant leap to think there could be more. One can wonder whether purifying water in our municipal systems while reducing transmission of the really nasty "bugs" has also eliminated many/most of the ones we evolved to have in our bodies. Has eliminating these good bacteria, protozoa, etc... had a deleterious effect on our general health? Could many of our other diseases be a result (or made worse) due to having our intestinal flora out of balance? IIRC, our appendix served as a bacteria well to jumpstart our intestinal flora when needed. It became a vestigial organ as man started to live in larger and larger groups. We could then get our jumpstart just from being near others. With the constant purification of our municipal water, is it possible that drinking wild water could actually be beneficial to our general health? Is it possible this benefit outweighs the potential risk of "contaminated" water especially that which is found deep in the wilderness?

Not so far off topic - I live with dogs. My dogs can get in and out on their own and have a very large space (in a forest in the country) to play in. In short, I am exposed to everything on the ground in my dog yard via my dogs appreciative kisses
. Am I healthy? Yes very.

I got one o' them ultraviolet light thingies and used it in clear mountain stream water with no ill effects. I guess ya just sick it in yer mouth while ya drink...
Aimless - I WAS a very long way from a large population center...
Jim

Aimless - I WAS a very long way from a large population center...

When I am in the high Wallowas and there's not much above me but snowfields or else there's a nice spring bubbling up, I'll sometimes drink wild water straight, no chaser, even if I have a filter sitting in my pack. The risk in a place like that is vanishingly small. Besides, it tastes sooooo good!

(I guess that means I lied when I said I "always" used my filter.)

I had to boil water the last three days (lake close to the trailhead and with no active outlet this time of year) because my Sawyer Squeeze turned out to be blocked. It worked just fine at home with tap water the week before! And I forgot the MicroPur tabs I usually take along. Fortunately I had plenty of fuel!

It couldn't be backflushed either?

The first trip I took this year, I didn't take the syringe to backflush, and it was blocked....really sucked. I carry the syringe every time now.

Suddenly I don't feel so bad about carrying that full (or mostly full) canister with me on an overnight!

After reading your line of questions I have to say you really summed up my own broader thoughts on this better than I ever could have. For me, right now it is impossible not to conclude there are huge and important benefits. I couldn't find a study that focused on that, but I'll keep trying.

Here are a couple good articles that describe how important gut flora is:

NY Times: How Microbes Defend and Define Us (DTape sent me this link. It's packed with info.)

Science Mag: Using Gut Bacteria to Fight Diarrhea (This describes some impressive progress on the above work)

When I consider the above, and then consider the likely effects Chlorine or Iodine have on gut flora, I have to conclude it's best to avoid them.

We know that water can contain some bugs that are bad for us, but as far as I can tell no one has ever looked for bugs that might be good for us. It's pretty near impossible for me to conclude there are none.



I plan trips around water sources, and have for years. Drinking good, pure, wild water is one of the pleasures in life I enjoy and appreciate most. The water here in the Ozarks is one of the main reasons I moved here.

This year has been especially remarkable. We've had huge floods in `08 and `11, and lot of hard downpours this and the years in between those. This has really flushed system, so to speak, and has resulted in visibility in our local lakes up to 50 ft. at times this year.

I know this is not an option for everyone all the time, but it's worth the effort to learn the skills of identifying good water, doing some research on locating sources, and experience bending over a cool running pristine stream or spring and drinking from it. There are probably few things in life you could do that would be better for you. Maybe someday our medical industry will study the effects of that.

Jim, they're contributing to your immune system too, no doubt about it. I've read that kids that grow up with cats and dogs, and those that play outside, have fewer allergies and healthier immune systems. Makes sense to me...

Depending on what else you may carry, the syringe isn't necessary. If you have the version with the nipple, you could connect a tube to a bladder to backflush.

Not in the field; I tried. Used the tube connected to water bladder, using boiled water. I will work on it at home now that I'm actually at home for the week. Considering that it was tested with tap water and worked just fine shortly before the trip, why was it blocked the first time I tried to use it in the field?

Good question. I'd try contacting Sawyer support and ask.

I have the older version. Plus, all my bladders are dirty. My syringe is pretty light, Plus I can use it to irrigate wounds.

Oregon Mouse,

I've had this occur several times within the last year and have talked with Sawyer about it. They recommended backflushing it under a hot water faucet and/or soaking it in vinegar then backflushing it. This has worked for me. Takes about a half hour of fiddling to restore full flow.

More recently I've been using the technique shown in the link below:

http://www.backpackinglight.com/cgi-bin/...t=683345#683345

For me the problem might have been associated with using bleach (per instructions on water bags) to disinfect the filter. Have you used bleach at all?

Sounds like they are worried about calcium or hard mineral build-up.

By the way DJ, love the high pressure hose technique.

I think that probably floaties sinkies and swimmies in the water clogged up the filter system so that may be the reason.
-Nate-

Nate,

I didn't mention this in my post but the problem occurs between trips not after trips. The filter would flow well after backflushing it when I store it. When I took it out of storage after a few months, however, the flow was greatly reduced. So I think the problem has more to do with some aspect of the drying process (in my case) than floaties etc in the filter.

Am convinced after three seasons of use that the Sawyer cartridges cannot be completely dried. Even after weeks sitting in a sunny window I can still get water drops out of them.

My takeaway is it's very important to do the chlorine solution backwash before storing for the winter, then at the season's start, backflush before the first trip.

Some combination of bacteria and/or mildew is at work during that off period, clogging the works.

As to how visibly clear water clogging the filter in the field, it's likely to be bacterial biofilm. Have found field-backwashing can restore flow, even though it's a pita to do.

Cheers,

Rick,

"Am convinced after three seasons of use that the Sawyer cartridges cannot be completely dried. Even after weeks sitting in a sunny window I can still get water drops out of them."
I agree and someone awhile back actually cut one open and confirmed same. Was that you?

"My takeaway is it's very important to do the chlorine solution backwash before storing for the winter, then at the season's start, backflush before the first trip."
I also agree with this and it is what I've done in the past. The reduced (almost no) flow problem occurs when I remove it from storage and am preparing it for that first trip. That's when I have to backflush, forward flush, soak in vinegar, etc. Takes about a half hour of fiddling to get it flowing correctly again.

"Some combination of bacteria and/or mildew is at work during that off period, clogging the works."
Maybe so. I don't really know the cause. Others have guessed it is the bleach or Seattle water.

"As to how visibly clear water clogging the filter in the field, it's likely to be bacterial biofilm. Have found field-backwashing can restore flow, even though it's a pita to do."
Haven't had a flow problem in the field yet and I've used it for up to a week at a time.

So far this year my pressure nozzle backflush (see link in post above) before and after each trip has kept things flowing nicely. Won't be putting it into storage again until Oct so we'll see what happens next spring.

In one of the links above, a poster made this comment,"Most of the reports of the Sawyer filters slowing to a crawl (my inline did this) are when the filter dries out in storage, not usually on a hike."