Re: Water Treatment Tablets

Do iodine tablets for treating water for drinking ever go bad? I have some with no expiration date on the bottle, but I want to make sure.

Not Really. If they are intact, not a pile of fuzz at the bottom of the bottle, they should be good.

The residual flavor of one tetraglycine hydroperiodide 8mg tablet per liter of water can be removed by adding 50mg of vitamin C per liter AFTER treatment. One 1/4 tsp of powdered vitamin C (ascorbic acid) weighs about 1 gram so 50mg is just a pinch. Even if you used an entire gram in a liter of water it would give the water a slight lemony taste. Add a little sugar and it's quite good.



Post Edited (06-04-07 20:04)

---

Old Dude

What is the recommended way to add vitamin C? Should I just grind up a chewable vitamin C tablet, or is there some other form that is more effective?

We usually buy this set:

Potable Aqua Iodine and Taste-Neutralizer Tablets $8.50
http://www.rei.com/product/406032

It says you put two of the "neutralizer" tablets in after the iodine, but usually one is enough if you want to stretch it. You do have to wait awhile before you put in the vitamin c tabs/neutralizer tabs... can't remember the length of time.



Post Edited (06-04-07 10:55)

letterknit wrote:

> We usually buy this set:
>
> http://www.rei.com/product/406032
>
> It says you put two of the "neutralizer" tablets in after the
> iodine, but usually one is enough if you want to stretch it.
> You do have to wait awhile before you put in the vitamin c
> tabs/neutralizer tabs... can't remember the length of time.

At least 30 minutes after the iodine, which is the time they recommend for killing giardia. There's no reason it can't be left overnight. I suppose that it not only removes the offending taste, but also neutralizes the disinfecting capability of the iodine. They say five minutes should be enough, and it's 45 mg of ascorbic acid per neutralizer tablet.

Oh - I forgot to post their FAQ earlier:

http://www.potableaqua.com/potable-aqua-faq/

I'm looking at my unopened bottle of Potable Aqua P.A. Plus, and the date code on the iodine bottle is 30632, which I believe makes it the 32nd batch made in March 2006.



Post Edited (06-04-07 11:05)

We bought some of this Polar Pure iodine, but haven't used it yet. Anyone else have it and like it?

http://www.polarequipment.com/

There are different types of iodine tablets. Potable Aqua brand uses the aforementioned tetraglycine hyperiodide; it's their proprietary formula. They also sell their Potable Aqua P.A. Plus which comes with two bottles including the vitamin C taste neutralizer tablets. I don't know exactly how much vitamin C is in their tablets, but they're about the size of their iodine tablets.

They're not required to have an expiration date, but recommend it be opened no more than four years after manufacturing, and used within one year of opening. Their FAQ has information on their date codes and what color a "good" tablet should be.

Iodine tablets are not effective for killing the cryptosporidium cyst. Crypto is known to be in all water sources in the United States. Use a mechanical filter even if you treat your water with iodine.

---

Old Dude

mrcondron wrote:

> Iodine tablets are not effective for killing the
> cryptosporidium cyst. Crypto is known to be in all water
> sources in the United States. Use a mechanical filter even if
> you treat your water with iodine.

The only chemical treatment that's supposedly effective against crypto is something that generates chlorine dioxide. I believe Katadyn Micropur MP1 and Potable Aqua Chlorine Dioxide are relabeled versions of the same product. There are also the portable chlorine dioxide generators (like MSR's Miox) that generate a solution from salt and water, but that seems like something way overpriced. I supposed chlorine dioxide generation on an industrial scale makes sense, but for small drinking water supplies, the tablets make more sense.

The four hour wait while these tablets work on killing crypto makes them almost usable for my tastes. I'll stick with my PUR Hiker.

---

Old Dude

I use a Sweetwater filter, weighs about a pound, pumps about a quart a minute, and I bring the Potable Aqua two-step system as a backup in case the filter breaks. Quicker results, safe, you can retrieve even muddy water, and the filtered water tastes real good after running it through the charcoal!

Letterknit asks:

> We bought some of this Polar Pure iodine, but haven't used it yet. Anyone else have it and like it?

We have used it in the past. My main worry about it is to be sure not to
accidentally put any of the crystals directly into the water to be purified.
You only want the solution.

It has the advantage of having a semi-infinite shelf life, as opposed to
tablets.

It leaves the water with a yellowish color...yum.

I read an article somewhere that argued that the odds of getting sick
from mountain water on any given day are very low. It argued that the
main cause of illness on the trail is due to cleanliness. He suggested
bringing some Purell hand sanitizer instead of filtering or chemically
treating drinking water.

I tried a quick web search, but was not able to find the article.

Personally, I was convinced that using hand sanitizer is probably more
important. But I would still use a mechanical filter whenever possible.

Getting sick from contamination on your hands is probably the single most likely cause. If you use poles and touch the pointy end you might pick something up from the horse droppings. Everything you touch has been touched by someone else. Avoid actually touching your food. Use the wrapper on bars, use a spoon or fork when eating, and if you drop something on the ground blow the dirt off before you eat it.

I take a stock of latex gloves and adult butt wipes (in the adult diaper section) along with TP. I pull the latex glove over the wipe when finished and deposit that into a zip lock sandwich bag and then into a gallon freezer zip lock. The whole mess goes into the garbage when I get to a can.

I also take alcohol wipes for use when I think I might have contaminated my hands. These are also useful for sterilizing instruments when it's necessary to remove a splinter or treat a blister. They can be found in the diabetes section of any drug store.

---

Old Dude

Yeah, I'm thinking it was a bad purchase... the last time we didn't bring it because it seemed too heavy (short trip, pills lighter). I initially got it because at the time it was the only kind they had at the store I went to. I also thought it would be a fun experiment... something exciting to figure out in camp... reading all those instructions and filling the bottles, gauging the temperature, etc. In hindsight, sounds like a hassle.

I think they told me at the store that the Polar Pure was better because you use a more accurate measurement of iodine since the amount you use is based on the temperature of the water.

I've done some serious reconsideration regarding drinking from streams recently, thanks to some reading on the Mt. Whitney board.

As a kid in Colorado, we always used rivers as a drinking water source, using the simple principle of catching it where it flows quickly, preferably over rocks, and of course using common sense as to what's upstream. Since there were never any ill effects, I continued to do this in California and the Sierras. Then suddenly I "heard" about all the giardia cases and how it was "so prevalent" in the streams.

The fact may very well be that it is all a bunch of anecdotal misinformation..."I drank from the river and got sick a few days later". Without a sample of the water, it is impossible to attribute it to the water, and in fact camper hygiene may be the source of most or all of these reported "incidents".

Having discussed this with enough people who "drink smart" but don't use filters or iodine on a regular basis, and read enough to see where this idea originated, I've changed my attitude toward those pure rivers from snowmelt, such as the Merced, at least above the valley. Last week's Half Dome trip had me with a tin cup and happily drinking that icy cold wonderful water right from the Merced, and refilling the water bottles there before we headed away from it.

I do have a Katadyn filter and did use it on the way down at the spring near the 2-mile sign; with people splashing their faces and who knows what there, it just seemed safer. But looking at that icy Merced, I just can't believe it's teeming with giardia. In fact, some tests showed that SF's drinking water actually had a higher count of giardia than the Merced.
http://www.yosemite.org/naturenotes/Giardia.htm

I'm not necessarily advocating anybody do this, but for me, it sure felt good to drink from a clean river again without having to get out the filter and pump it; the water tasted great (as it does through a filter), and infinitely better than anything that's been "iodine-ized". I'll still carry a filter and use it when it appears there's doubt, but that river looks good to me.

One interesting thing I learned about lakes was that the UV sun's rays work on the top to actually purify it, so if you have to use a lake, try to get the water from the top inch or two, rather than deep. Personally, I think I'd use the filter on a lake if I had one available, otherwise I'd sure look around carefully for anything nearby that might be contaminating it. Then carefully fill my cup/bottle from the water at the top.

---

Gary
Yosemite Photo Galleries: http://www.pbase.com/roberthouse/yo

Here's another tidbit.

Giardia cysts sink. Lake water is less likely to get you than stream water. Deer are carriers as are beavers along with humans so the likelihood of cysts getting into streams is quit high. Unless you see the actual snow melting into your cup you stand a better chance of ingestion from a stream than from a lake. When water gets down to a large flow like the Merced everything is concentrated there.

I wouldn't drink the water that crosses the Half Dome trail without filtering. It gets pretty gamy later in the year especially with people using it to wipe down on hot days. There is a spring at 34-44'57"N 119-30'50"W. The pipe can be found. We've camped there a couple of times.



Post Edited (06-05-07 10:36)

---

Old Dude

Here's a link to more info, including an updated article by Bob Rockwell on the subject
http://highadventure.bsadpc.org/wisdom.htm

This is a more heavily-referenced and thorough version; if it's too much reading to interest you, you can skip down to the "So what about the Sierra Nevada" paragraphs in the middle, which gives some interesting statistics.

One interesting observation was that though beavers are susceptible to giardiasis, there is some indication that they are the victims...from human campgrounds upstream of them.

There are a lot of ways to look at the lake/stream issue. Water in a lake may have little circulation, other than a 'route' from inlet to outlet. If a contaminant gets in, and you 'dip your cup' in that vicinity, you get a much higher concentration than if it were dispersed throughout the lake. The flowing action of a river is constantly diluting anything that mixes in, not to mention the filtering from running over rocks or sand.

It's important to read enough to understand that Bob isn't advocating just drinking whatever you find...it's a common-sense thing, or "drink smart" as he puts it. When in doubt, treat or filter, but he just challenges the paranoia that we've been subjected to about the Sierra water being contaminated or dangerous.

---

Gary
Yosemite Photo Galleries: http://www.pbase.com/roberthouse/yo

Letterknit, I would not throw out the iodine. It is excellent for earthquake supplies, because it will never 'expire'. The other advantage of the iodine is rated to kill viruses. So if you suspect viral contamination, you will want the iodine. Still, I prefer to use a filter when there is any question about the water safety.

Another issue I have with purification by chemicals is that if there is a chunk of something in the water, that chunk may contain contaminants inside.

Gary, thanks for sharing that article. That just might be the one that I read before but could not find in a search. In any event, it has the same message and with compelling data. Anyone can have an opinion, but supporting data is very convincing.

I think that having a small traveller-size bottle of hand sanitizer is essential. I have noticed these days that this is what is used in hospitals and doctors offices. No water required, although I would rinse my hands to remove dirt.

RobE wrote:

> Letterknit, I would not throw out the iodine. It is excellent
> for earthquake supplies, because it will never 'expire'. The
> other advantage of the iodine is rated to kill viruses. So if
> you suspect viral contamination, you will want the iodine.
> Still, I prefer to use a filter when there is any question
> about the water safety.
>
> Another issue I have with purification by chemicals is that if
> there is a chunk of something in the water, that chunk may
> contain contaminants inside.

Boiling takes care of everything, although some people might be squeamish about consuming even heat disinfected fecal matter. I plan on bringing along some cone coffee filters to filter out the little bits before chemical disinfection.

> Gary, thanks for sharing that article. That just might be the
> one that I read before but could not find in a search. In any
> event, it has the same message and with compelling data.
> Anyone can have an opinion, but supporting data is very
> convincing.
>
> I think that having a small traveller-size bottle of hand
> sanitizer is essential. I have noticed these days that this is
> what is used in hospitals and doctors offices. No water
> required, although I would rinse my hands to remove dirt.

I remember bringing the subject up of alcohol gel or benzethonium chloride wipes on rec.backcountry. There was this one poster who was adamant that it was foolhardy to trust that it would work. Her opinion was that one had to avoid touching food/beverages/eyes/mouth at all costs unless there was a clean source of water to wash one's hands.

I think it's a sensible choice when there is no alternative to hand washing. I'll actually use some on my hands before using a pit toilet.

RobE, good thoughts about the earthquake supplies, I hadn't thought of that. Too bad I'm moving back to Chicago this summer.

Do you have to keep water in the bottle at all times? The website said something about the iodine crystals evaporating or disintegrating or something. We've never used it or put water in it. And it's not hermetically sealed or anything.

letterknit wrote:

> Do you have to keep water in the bottle at all times? The
> website said something about the iodine crystals evaporating or
> disintegrating or something.

As long as the bottle is air tight iodine crystals will keep. I still have some I bought in the early 80's.

Letterknit wrote:

>RobE, good thoughts about the earthquake supplies, I hadn't thought of that. Too bad I'm moving back to Chicago this summer.

Thanks. But won't that be a long commute to Yosemite??

>Do you have to keep water in the bottle at all times? The website said something about the iodine crystals evaporating or disintegrating or something. We've never used it or put water in it. And it's not hermetically sealed or anything.

It is important to keep the iodine crystals underwater to prevent sublimation. You don't want iodine gas. That would be bad.

Remember that the chemicals used to sanitize water are rather nasty. Drinking water is generally treated with chlorine and chloramine. Chlorine
is a very dangerous gas, but only occurs in your drinking water in very
small quantities.

When you use the iodine to sanitize your water you are using a very small,
measured amount (according to the instructions on the bottle and the
iodine solution temperature). Iodine is not very soluble in water, so
you only add a very small amount of actual iodine.