[SgtDice]

This is a real interesting read.
http://indefinitelywild.gizmodo.com...e-bull****-and-so-are-some-filters-1704387492
I personally would pre-filter any water I want to treat from exp and reading into the fine print.
And feel that nothing beats boiling water for 5 minute's.

Hope someone learned something from this.

 

[DaFireMedic]

The guy has an interesting perspective, but he's a bit off base in his conclusions. Granted, UV purifiers are not perfect, they have their downsides (as do the other treatment methods), but they have significant advantages as well.

It really depends on where you are at. Maybe I just haven't encountered that situation in the Western States where I frequent, but in 40 years of hiking I've never had to purify or filter truly murky water, even from lakes. If I did, I would pre-filter it, but I've always been able to select relatively clear water sources, even in drought stricken California. I have filters from Sawyer and Katadyn, and I can't speak for the Camelback UV purifier as I've never used it, but the SteriPen is my usual choice, especially in the Sierras where the water is some of the most refreshing in the world IMO, and the SteriPen is the only water treatment method (except maybe now the CamelBack) that doesn't affect the taste of the water. There are times when I use a filter, but I prefer the SteriPen in most cases.

I had several friends take SteriPens to Haiti for relief work right after the earthquake when Cholera and other water-borne diseases were running rampant. They drank the water (UV treated) there for 2 weeks without issue.

The area that where I agree with the guy is that UV purifiers are electronic devices and are subject to the problems that can accompany electronic devices in the wilderness. In the Sierras, complete failure of the device is not as much of an issue as I only started treating water there a few years back and have never been sick from it, but I always carry a few individually wrapped tablets as back up, and can boil water also if needed. But you do have to take into account the charging or replacing of batteries as well, depending on how much water you need. Again, SteriPens are not perfect.

Boiling water is fine when car camping or if only going short distances and fires are allowed, but is impractical for most people to rely on when hiking more than a few miles. You would have to consider how much stove fuel it would take, or build a fire (not allowed out here) at every water stop. Also, depending on the size of your cook pot, one boil may not be enough to get you to the next water source and you may need to do several boils. Boiling water is still an option, but with the treatment options available today, it usually isn't necessary or practical for most backpackers.

 

[azb]

In addition to what dafiremedic said about boiling, it also takes quite a bit of time to boil water, let it cool, etc. Not a big deal in a static camp, but if you're on the move or trying to get things done it is a problem.

I read Sawyer's response to the claims about their filter in that blog. They expressed concern that the folks in Africa where those filters were tested had fouled the clean side of the filter and that's where the contamination tbat was experienced came from. They also mentioned that it looked to them like the fiber damage had occurred when the filters were cut open, as the damage resembled being cut more than ruptured.

At any rate, the tests were poorly controlled and Sawyer welcomes anyone who is interested in properly testing their filters.

It's worth reading both sides of the story.

Az

 

[FreedomHunter]

In addition to what dafiremedic said about boiling, it also takes quite a bit of time to boil water, let it cool, etc. Not a big deal in a static camp, but if you're on the move or trying to get things done it is a problem.

I read Sawyer's response to the claims about their filter in that blog. They expressed concern that the folks in Africa where those filters were tested had fouled the clean side of the filter and that's where the contamination tbat was experienced came from. They also mentioned that it looked to them like the fiber damage had occurred when the filters were cut open, as the damage resembled being cut more than ruptured.

At any rate, the tests were poorly controlled and Sawyer welcomes anyone who is interested in properly testing their filters.

It's worth reading both sides of the story.

Az

Thanks for the info. I can't stand this crap science in this day in age where people setup these rigged experiments then draw false conclusions because they never set up the experiment correctly in the first place. I have probably spent a few hundred hours trying to figure out ways of purifying water. I'm not that satisfied with any of the research that the FDA or anyone has to say. But at least it's better than no research at all.

I have used iodine to purify water on hikes before and it works well enough for me. The FDA says you can use diluted bleach as well, which I have never used, but I prefer the chemical solutions to this problem that are simple and light weight to carry. 1 ounce of iodine could last you for practically a whole month in the woods. I have never had to filter muddy water either, but that's why I always keep bandanas (cheese cloth) on me as they work well enough as a cheap filter. I have used a bandana on clear water and have ended up with no debris in my water bottle.

I can tell you when I lived in Mississippi, the public water companies used chlorine to treat the water because you can smell it strongly in the drinking water. Also when you go to take a shower, you can feel the water feeling "slimey". I figure if they can treat that nasty Mississippi swamp water with chemicals, then it's probably the best way to treat drinking water. I have never heard of a water treatment plant yet using UV to treat drinking water.

P.S. I have never gotten sick from drinking water that I have brought to a boil for 30 seconds. The FDA recommends a minute or so? I don't remember the exact time, but 5 minutes seems excessive and wasteful of water that would evaporate. I'm pretty confident that any bacteria will die after bringing the water to just when it starts bubbling as the temperature for most bacteria to die is well below 212F.

 

[franklin]

One of my hiking partners is a microbiologist who works for a pharmaceutical company on medicines to treat infectious diseases. Years ago when First Need and Katadyn filters where the main ones on the market he tested them. (His lab uses laboratory grade filters to purify water for lab experiments and has the ability to test filters.) He found that the Katadyn unit removed virtually all micro organisms and the First Need removed larger complex organisms usually involved with human health issues. Both met their published spec on particle size.

The Sawyer units available today have better specs than the First Need so it should work well. That's the one we use today. (Probably should get him to run another test sometime.)

I have used a First Need filter along with a pre-filter to decontaminate some nasty looking water from a bog. Even if I would have boiled or chemically treated that water I would have wanted to do some amount of filtering.

I use a filter about 90% of the time I need water purified.

 

[DaFireMedic]

P.S. I have never gotten sick from drinking water that I have brought to a boil for 30 seconds. The FDA recommends a minute or so? I don't remember the exact time, but 5 minutes seems excessive and wasteful of water that would evaporate. I'm pretty confident that any bacteria will die after bringing the water to just when it starts bubbling as the temperature for most bacteria to die is well below 212F.

I read from some health organization that all known waterborne pathogens die immediately at 194 F, and as low as 140 F if the temp can be maintained for a given period of time. The 1 minute that the CDC recommends is likely because it is then clear that the water has reached at least 194 degrees.

There are other organisms that can survive in those temps, but none of them are pathogens and do not make us sick.

 

[TMcArthur]

161 F for 15 seconds is good enough. I don't bring a thermometer with me so I figure once it has started to boil, I'm done.

If you have lots of time, if the water is clear all you need is a clear plastic water bottle and a sunny day.

 

[TMcArthur]

That's 140 F for 20 minutes for proper Pasteurization.

The idea is that you do not need to kill 100% of pathogens to be safe. Pasteurization doesn't kill all the harmful bugs but it does kill most (99.99999%) and the remainder are so few they can't make you sick. That's why pasteurized milk doesn't last forever even when refrigerated. Eventually that .000001% recovers from the shock and starts multiplying again.

 

[ROCK6]

I have no issues with UV, but like with many of the chemical means, pre-filtering is always important. I used the MSR MIOX in some pretty bad places, but went the extra mile to allow sediment to settle and pre-filer as much as possible. The efficacy is often dependent on the degree of turbidity. Still, very few devices beat the simplicity of the Sawyer as a filter or boiling for purification.

ROCK6

 

[ljcygnet]

I've gotten crypto from water treated with iodine -- infectious disease doc said it was resistant to iodine and chlorine and he'd seen other cases from people who were backpacking and relying on iodine. For what it's worth. I was sick enough for long enough that my doc sent me to that specialist for proper testing and diagnosis. Dang near ended up in the hospital.

Whenever possible, I boil my water. When I can't, I use the maximum dose of iodine and let it sit for a few hours. (Per that doc's suggestion.)

I've used filters with varying degrees of success.

And there have been numerous times when the only water available is murky for me when hiking. Joys of hiking in the desert southwest. (Drink the stock pond water or die of dehydration? Hmmm ... tough choice!)

The water that made me so deathly sick was from a reasonably clear creek, however -- full of tannins and suspended sediment, but not stagnant. It's cold and healthy enough water to support pretty respectable sized brown trout.

 

[Hick Industries]

I purchased one of the first low cost units with a sealed filter elements in the early '90s, and plugged the filter on the first day of a week long hike.

I spent the rest of that trip using wood fires to boil my water, Grrrrrrrrrrr.

When I returned, I bought a Katadyne and later a MSR.

I still have to disassemble it and clean the mud off the ceramic element.

But it always works and I dont have to start a fire.

 

[ilgar]

Here is an excellent comparison chart, include price, value output, weight, durability, speed, etc.:

http://www.outdoorgearlab.com/Backpacking-Water-Filter-Reviews/ratings

My favorite is melting snow which is not listed...

What sucks is that chemical contaminats would not be removed in either process. so you just have to know where you are to make sure there isnt agricultural or mining or other industrial/pesticide runoff.

My choice was first need xle. although sawyer is obviously the most popular nowadays.

 

[dmas]

I've gotten crypto from water treated with iodine -- infectious disease doc said it was resistant to iodine and chlorine and he'd seen other cases from people who were backpacking and relying on iodine. For what it's worth. I was sick enough for long enough that my doc sent me to that specialist for proper testing and diagnosis. Dang near ended up in the hospital.

Whenever possible, I boil my water. When I can't, I use the maximum dose of iodine and let it sit for a few hours. (Per that doc's suggestion.)

I've used filters with varying degrees of success.

And there have been numerous times when the only water available is murky for me when hiking. Joys of hiking in the desert southwest. (Drink the stock pond water or die of dehydration? Hmmm ... tough choice!)

The water that made me so deathly sick was from a reasonably clear creek, however -- full of tannins and suspended sediment, but not stagnant. It's cold and healthy enough water to support pretty respectable sized brown trout.

Crypto is a spore with a shell that protects it, it can stand straight household bleach. A filter is the standard means for protecting against it, boiling also works. However my understanding is it is not dangerous unless your immune system is compromised.

Iodine requires more time to work if the water is cold. But again not that effective against crypto.

 

[elmojo]

I've gotten crypto from water treated with iodine -- infectious disease doc said it was resistant to iodine and chlorine and he'd seen other cases from people who were backpacking and relying on iodine. For what it's worth. I was sick enough for long enough that my doc sent me to that specialist for proper testing and diagnosis. Dang near ended up in the hospital.

Whenever possible, I boil my water. When I can't, I use the maximum dose of iodine and let it sit for a few hours. (Per that doc's suggestion.)

I've used filters with varying degrees of success.

And there have been numerous times when the only water available is murky for me when hiking. Joys of hiking in the desert southwest. (Drink the stock pond water or die of dehydration? Hmmm ... tough choice!)

The water that made me so deathly sick was from a reasonably clear creek, however -- full of tannins and suspended sediment, but not stagnant. It's cold and healthy enough water to support pretty respectable sized brown trout.

Maybe the trout made you sick.

 

[ljcygnet]

Maybe the trout made you sick.

Didn't eat any on that trip. I'm not a big fan of trout. (Heresy, I know.). I did eat a mess of crawdads, but they were very thoroughly boiled.

Anyway, I was definitively diagnosed with crypto, which is waterborne and not food poisoning.

I was on immunosuppressants at the time, yes, though not enough to be worried about getting sick from what I thought was properly treated water. (I have rheumatoid arthritis and was on prednisone and methotrexate at the time, but they were fairly low doses.) It might have contributed to the degree I got sick, though, certainly. One doc said 'no' and another said 'yes' as far as it being a contributing factor.

Many people have compromised immune systems. Sometimes -- probably often -- they don't even realize it.

 

[vicdotcom]

I read Sawyer's response to the claims about their filter in that blog. They expressed concern that the folks in Africa where those filters were tested had fouled the clean side of the filter and that's where the contamination tbat was experienced came from. They also mentioned that it looked to them like the fiber damage had occurred when the filters were cut open, as the damage resembled being cut more than ruptured.

I eventually did switch to Sawyer as my primary filter. But it took me years due to that fact. There is NO WAY TO KNOW IF THE FIBERS ARE DAMAGED. I even emailed them to ask if there was a way to know if the fibers are damaged and they replied that there was not.

Now it is is cheap enough to purchase 10 filters. But still a question remains in my mind about it at times.

Yes there are two sides to the story but there is still no way to know if the filter element has been compromised or not.

 

[TMcArthur]

I always try to pack a few Mr.Cofee filters just in case I need to filter out some chunks. Multiple layers of linen work too.

 

[Stinky]

There would be a way to test the sawyer but it would need to be provided on a commercial level, I don't think a consumer could develop it properly.
If the filter pore size is (?) .2micron then all that should be necessary is to test with a colored agent that has a particle size of .2micron. If the agent is filtered your filter functions properly.
IIRC the 1st. need filter tests with colored dye.

 

[Vanishing Nomad]

I read from some health organization that all known waterborne pathogens die immediately at 194 F, and as low as 140 F if the temp can be maintained for a given period of time. The 1 minute that the CDC recommends is likely because it is then clear that the water has reached at least 194 degrees.

There are other organisms that can survive in those temps, but none of them are pathogens and do not make us sick.

It may also be to ensure it's a real boil. I know on a stove, water will boil on the outer edges of the pot, but be cool in the center. You can see this if you stir the water and watch the boiling process stop as the cooler water mixes in.

I feel a better way to be sure, rather than a fixed amount of time, is to stir the water. If it does not stop boiling, it is done. But if you can stirr it, and the boil process stops, or significantly slows down, it's not ready yet.

 

[ncbill]

Pre-filter with something like disposable coffee filters.

Then use your filter of choice, use chlorine or iodine if worried about virii, finally filter through carbon for better taste (especially if you used iodine).

Sawyer filters are cheap enough to toss after a trip, rather than bother with back-washing.