All of the filters will remove bacteria. If you are looking for the most thorough filter, the First Need purifier would be "it" - it also filters viruses. Not even a bacterium smaller than .2 microns would slip through.
It appears that it's most often a danger when you're swimming in the water. So filter and don't swim.
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"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki
I'm not sure that even the First Need will "filter" viruses; most of them are smaller than 0.2 microns (200 nanometers). Viruses are generally less than 100 nanometers in diameter. For example, the equine encephalitis virus is about 60 nanometers in diameter while the bacteriophage viruses Ψ174 and PRD1 are 23 and 63 nanometers in diameter respectively. From what I have been able to find, Leptospirosis is less than 25 nanometers in diameter. Perhaps the first need has some sort of iodine bed treatment for viruses in addition to its filter.
A micron is 1/1,000,000 of a meter, a nanometer is 1/1,000,000,000 of a meter.
The best thing to use against virus is something like ClO2 (Micropur) or UV light (Steripen). Personally, I would not trust claims about filtering viruses.
Leptospirosis is a bacteria. It is found in rodents, dogs and also humans. You can call the manufacturer of whatever filter you have/want and see if it covers this type of bug.
I use bleach to kill anything the filter didn't get, if I filter at all. Any of the chemical water treatments should do the trick. Bleach is cheap and is what my muni water department uses.
Leptospirosis is a bacteria. It is found in rodents, dogs and also humans.
Yeah, I didn't mention that did I? Still, the data I found indicate that it is small, around 25 micrometers in diameter.
If I suspect that there is virus contamination of the water I am using, I will treat with a chlorine source after filtering to remove potential Giardia or Cryptosporidium cysts.
When I was working in Morocco a while back, a colleague got hepatitis from drinking filtered, non-chlorinated water. I don't want to go through what he did so I double treat if at all in doubt.
Just generally, I tend to be a bit skeptical of a lot of filter claims. I mean, they are not the ones who suffer if their product is, for some reason, slightly below specifications, are they?
Just generally, I tend to be a bit skeptical of a lot of filter claims. I mean, they are not the ones who suffer if their product is, for some reason, slightly below specifications, are they?
I think about this a lot too. But I also think about the real vs imagined prevalence of "stuff" in the water and the folks I've hiked with who just dip water out and drink who are still out hiking and not sitting on the throne at home suffering for it.
Selection of water source and being prepared if the only thing available is a tepid, low flow spring that's being collected in a moss filled trough is about it. I have added Micropur tabs to filtered water before, I'll probably add boiling to that if I'm really skeeved by the look of the source. Something to be said for educating yourself on water sources prior to the trip.
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"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki
Registered: 02/03/06
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Loc: Gateway to Columbia Gorge
Actually, most municipal water departments use chlorine dioxide, not sodium hypochlorite (chlorine bleach), which, I've been told, can leave some nasty compounds behind it.
My-daughter-the-veterinarian told me that to prevent leptospirosis, I should keep my dog out of stagnant ponds or small lakes that have no outlet, especially when cattle are present, and treat his water from such sources. This is a good rule for humans, too! There is a canine vaccine for leptospirosis, but it often causes severe reactions and, per the University of California at Davis School of Veterinary Medicine is not very effective. My dog is actually owned by Canine Companions for Independence, even though he was rejected as an assistance dog, and they do not allow their dogs to get the lepto vaccine.
I would assume that the same rules apply to humans. If you're in cattle country, take along some chlorine dioxide tablets (I take some anyway in case something happens to my filter), and resist swimming in lakes with no outlet. The filter will take care of the protozoa that chemical treatment takes 4 hours to zap, so you only need 20-30 minutes' chemical treatment to kill bacteria and viruses.
I did a little googling but couldn't find out if lepto bacteria are of a size that most filters will remove. Thanks for finding this out!
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May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey
I agree with ya, Pika. Some viruses are pretty small and not filterable. I use my Steripen or the tablets, depending on where I am and how much water is available.
Something to be said for educating yourself on water sources prior to the trip.
Right. I think this is one of the benefits of experience; thinking about water sources before the trip. It is almost mandatory here in Arizona. I do a lot of spring, early summer and autumn hiking in desert mountains and cattle country. Mostly there is no flowing water, it is usually found only in water pockets or murky pools. So, I generally and routinely use a filter followed with Micropur tablets. When the water, after filtering, is the color of urine, or tea, one feels the need to do a bit more with it before drinking. I need to clean the filter a lot also; up to two times per liter. Once in the Grand Canyon I took water from a small pool with a dead coyote floating in it: no real alternative. I also carry a lot of water if the need arises.
Sometimes I think a person could gain weight by drinking Arizona mountain water straight, without treatment, if they didn't get sick first. There is probably 100 calories per liter of critterhood swimming in, and just soaking in the sources.
In the summer and early fall, I generally spend 2-3 weeks and 2-3 trips in the Sierra. There, I will use a Steripen or filter when I am mostly in popular (crowded) areas. I like the Steripen but don't trust it entirely. Otherwise, I don't treat the water at all if I have a good idea of what is upstream. On my trips to more remote places, I leave the water treatment machinery at home. If in doubt, I'll drop in a Micropur tablet.
Up until about ten years ago, I never treated my water at all unless it really looked bad. Then I would boil it. I don't recall ever getting sick: well, once when I was in the Army I picked up a case of amoebic dysentery in North Carolina from drinking contaminated water. I suspect that, in over 60 years in the hills, I have developed resistance to some of the more common bugs.
Lori is correct. Bleach is not considered effective against crypto and giardia. Nor do municipal systems use it. Older systems use cholrine (in gas form, I think) and as time goes on, municipalities are moving to chlorine dioxide which is effective against the above. A prime reason for the change was the breakouts of giardia from treated municipal water of sytems using the older chorine treatments. The incidence of giardia breakouts has been sigificantly reduced with the chlorine dioxide treatments. Many (most?) of the upgraded systems have also added UV treatment as a final 'dose' for the water.
When it comes to filters the main thing is size. What is the size of the threat and does the filter filter out buggies of that size? Specs from the manufacturers I've looked at give that information.
FB
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"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution
I'm not sure that's true, at least in the States. I can't name a single California city using it. I believe it fairly common in Europe, but to the best of my knowledge chlorine (either via Cl gas or sodium hypochlorite) and chloramine are the usual chemical treatments here. ClO2 has some issues with transportability and usually must be manufactured on site. It is commonly used in paper manufacturing though.
That's not to say it isn't better than chlorine or chloramine.
Cheers,
Rick
Originally Posted By OregonMouse
Actually, most municipal water departments use chlorine dioxide, not sodium hypochlorite (chlorine bleach), which, I've been told, can leave some nasty compounds behind it.
My-daughter-the-veterinarian told me that to prevent leptospirosis, I should keep my dog out of stagnant ponds or small lakes that have no outlet, especially when cattle are present, and treat his water from such sources. This is a good rule for humans, too! There is a canine vaccine for leptospirosis, but it often causes severe reactions and, per the University of California at Davis School of Veterinary Medicine is not very effective. My dog is actually owned by Canine Companions for Independence, even though he was rejected as an assistance dog, and they do not allow their dogs to get the lepto vaccine.
I would assume that the same rules apply to humans. If you're in cattle country, take along some chlorine dioxide tablets (I take some anyway in case something happens to my filter), and resist swimming in lakes with no outlet. The filter will take care of the protozoa that chemical treatment takes 4 hours to zap, so you only need 20-30 minutes' chemical treatment to kill bacteria and viruses.
I did a little googling but couldn't find out if lepto bacteria are of a size that most filters will remove. Thanks for finding this out!
Crypto and giardia are protozoa, not bacteria. They are much more resistant to chemical treatment because they are eukaryotes (i.e. complex organisms).
Leptospirosis is a spirochete (bacteria), which are prokaryotes, or simple organisms. Moreover they are gram positive, so they are more easily destroyed by antimicrobial chemicals.
I took a microbiology class this summer, and one of the exeriments we had to do was test the effectiveness of antimicrobial products on a bacteria. I discovered that chlorine bleach was mildly effective against E. coli, but hydrogen peroxide was extremely effective! I don't recall the water treatment product that contains oxygen, but it is one I would certainly lean toward. I didn't get a chance to test iodine (couldn't find it when I needed it!), but found that grapefruit seed extract was more effective than bleach, and lysol kitchen and bathroom cleaner was not effective at all!
In a similar experiment I found that Vietnamese cinnamon was extremely effective against E. coli (this is the real deal stuff that tastes just like a cinnamon red-hot candy, not the old stale flavorless stuff you get at Costco by the pound). I will be adding more cinnamon to my diet, that's for sure.
MNS
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YMMV. Viewer discretion is advised.
Crypto and giardia are protozoa, not bacteria. They are much more resistant to chemical treatment because they are eukaryotes (i.e. complex organisms).
It's not apples and fish - it's a matter of being thorough. If you use one water treatment method because it's effective against one of these things, and you come down with the other, you'll wish you had two effective methods to start with. It's important to know what you are using and why. Some methods are partially effective, some are more broadly effective. Personally I'd like to know if something I do is going to involve risk so I can make an informed choice.
Hawaii is an area of high risk for leptospirosis. That doesn't mean there's no risk of other common bacteria, or other "bugs." Avoiding stagnant water is the suggested preventive measure.
"Leptospira organisms are small, filamentous, motile, spirochetes coiled around an axial filament ranging in size from 0.1 to 0.3 µm in width and 6 to 20 µm in length. They are easily killed by disinfectants, heat, drying, and pH values below 6 or above 8."
The subject was "leptospirosis", not giardia and crypto, and....bleach is effective against those cysts if given enough time. It's used all over the world.
It is apples and fish... the question was about leptospirosis, which is a bacteria, and responders started talking about protozoa and viruses, which are managed entirely differently.
I agree that thoroughness is essential in many parts of the world anymore. Just a filter, or just chemical treatment might not be enough for many water sources. If you learn what you might encounter and know your enemy you can be prepared with the right treatment instead of a mixed bag you aren't sure will work.
MNS
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YMMV. Viewer discretion is advised.
Bleach is sodium hypoclorite. Bleach for short. No? Actually "Bleach" (and they use the word) is used to shock home water wells the world over, as well as swimming pools.
When discussing water treatments I'd say, 'No...sodium hypochlorite is not bleach.' Just as fluoride is not toothpaste and lye is not soap.
Household 'bleach' is generally 3-6% sodium hypochlorite and often contains scent additives which, of course, are not tested for, nor approved for, consumption. In contrast, concentration of the sodium hypochorite used by municipal water utilities generally runs 12-15%. It gained popularity with the utilities not only because it was easier to store than chlorine gas but was also much safer.
Utilities are slow to change and update their systems. But as the changes come, the older chlorine treatments are being replaced by chlorine dioxide which has been shown to be much more effective against buggies such as giardia and crypto. Some locations, which had large, multiple outbreaks of giardia traced to their 'treated' water, have not had a recurrence after switching to chlorine dioxide.
But don't let the word usage/definition issue cloud the issue. While bleach is great for surface disinfection and can be effective against baceria in water, the bottom line is...household bleach should not be relied upon as a water treatment if there is a concern for the presence of giardia or crypto (and probably any other virus as noted in one of the posts above).
FB
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"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution
Fiddleback, where are you getting your data regarding municipalities switching to clorine dioxide? Crypto and giardia are easily filtered, so I don't see the point of chemical treatment for those bugs.
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