water purification tablets - question

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SkinnyJoe

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I assume boiling water takes care of most bacterial life forms and viruses, but not chemical pollutants. Is this what tablets address? OR, does a person need some sort of filtration system or a distillation set-up for chemical contaminants?

In other words, what niche do the water tablets fill?

Who regulates or at least measures the quality of such items anyway? Any Consumer Reports issues that we should be aware of?
 
I'm pretty sure there isn't a simple tablet that can remove chemical contaminants.
 
SkinnyJoe said:
I assume boiling water takes care of most bacterial life forms and viruses, but not chemical pollutants. Is this what tablets address?
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tablets are just small and lightweight - rather than carry a heavy, bulky water filter some people opt for tablets. they're also convenient - just drop them in and wait. you don't have to work to filter a gallon of water. personally, i prefer water filters but i carry tablets and/or a small dropper bottle of bleach as backup.

SkinnyJoe said:
OR, does a person need some sort of filtration system or a distillation set-up for chemical contaminants?
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charcoal can bind with some chemicals and remove them to some degree - but to obtain pure water free of chemical pollutants you have to distill it as you guessed


SkinnyJoe said:
In other words, what niche do the water tablets fill?
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lightweight, small enough to fit in your pocket, convenient

if you're looking for water filters, i recommend MSR MiniWorks

http://www.msrcorp.com/filters/longevity.asp

someone else could maybe recommend tablets - i don't have much experience with them. i think micropur tends to be highly recommended.
 
There are two types of purifying tablets. Chlorine and Iodine. The biggest difference that I have found is the time required to take effect. They work very well against bacteria and viruses. The safest scenario is a combination of good filtration and good purification so in a full sized kit it is probably best to carry both. It is not really feasible to carry any filter that I know of in a mini kit so tablets are usually the order of the day. A bottle of Polar Pure which is also a bit big for a mini kit will purify and unbelievable amount of water and is Iodine based. MSR and Katydyn make the most popular pump type filters. Boiling is also excellent for viruses and bacteria so any kit mini or otherwise must contain the means (fire and container). I assume a filter of some sort could be improvised in a number of different ways. -DT
 
A couple of items about Iodine to consider. The iodine tablets do lose thier potency and should be replaced at least once a year and more frequently if opened. The Polur Pure is a suspension so it does not evaporate like the tablets do. Another thing is that iodine does not reliably kill cyrptospuridium (sp?). A filter rated at .2 microns or better will filter the microorganisms out however. Some people treat with iodine then filter. I personnaly have been using a filter only for nearly 20 yrs and have never had a problem. One thing to always consider though is your location and your water source. Extra precautions and steps may be necessary.
 
dttomcat said:
A good filter will remove most chemical contaminents but may not be effective against all viruses or bacteria. -DT
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Actually, most chemical contaminants are smaller than the microbes that cause illness, so a filter will be less effective against chemicals. I asked about this a little while back:

http://www.bladeforums.com/forums/showthread.php?t=485923

The consensus was that a filter with an activated charcoal section might remove some chemicals to some degree, but in general a backpacking filter would not be a very good way of treating chemically contaminated water. There were some other really good suggestions for products that would be better suited.
 
A footnote on iodine tablets: there is always the small risk of overdose. Children are particularly susceptible to it, so I would opt for chlorine if kids are part of the equation.

The only portable filtration that I would trust to remove chemical contaminants would be a hand-powered reverse osmosis unit... and those cost about $2k. :(
 
All the tablets are is a biocide. There are floculents (I know I'm not spelling that right) which attached to crud, but they generally bulky and powder based, and IIRC don't do much for the really scary stuff like heavy metals and pesticides.
 
Iodine is passe. Chlorine dioxide is the state of the art chemical. Don't be fooled by the chlorine in the name -- it doesn't taste of chlorine, it is the oxygen in the compound that kills the bugs. The chlorine in your household bleach is sodium hypochlorite -- very different stuff.

Aquamira, Katadyn Micopur, KlearWater, and Potable Aqua make chlorine dioxide produtcs. Potable Aqua has been a longtime supplier of iodine tablets, so don't get confused there. Contact time, temperature and turbidity are important factors with any chemical treatment. Prefilters can help with cloudy water sources. It tales a couple hours to be fully effective so having two containers can be handy-- one to treat, one to drink, rotating as they are used.

Filters need to be able work on bugs that are 0.3-0.2 microns. The filters they sell that are 2 microns are a joke, IMHO. Even with that, you won't take care of viruses, but chlorine dioxide will.

In North America, giardia and cryptosporidium are the major culrprits, and a decent filter will take care of them, but in other parts of the world you need to worry about viruses-- stuff like hepatitis and polio, and the usual bacteria like e coli and cholera.

For all the trouble and fiddling with filters and chemicals, IMHO any real survival kit needs a pot that you can boil water in. You might run out of chemicals or they might not kill the bugs in your locale, but boiling does the trick-- that and some careful handling so you don't cross contaminate.

Chemicals are tough to get rid of. Charcoal helps taste and will catch some stuff, but I don't think there is any free lunch with stuff like arsenic or cyanide from mining run-off, etc. I would want to know the area if that might be an issue--- "don't drink from Rio X below n thousand feet...."
 
DaleW said:
Filters need to be able work on bugs that are 0.3-0.2 microns. The filters they sell that are 2 microns are a joke, IMHO. Even with that, you won't take care of viruses, but chlorine dioxide will.

In North America, giardia and cryptosporidium are the major culrprits, and a decent filter will take care of them, but in other parts of the world you need to worry about viruses-- stuff like hepatitis and polio, and the usual bacteria like e coli and cholera.

For all the trouble and fiddling with filters and chemicals, IMHO any real survival kit needs a pot that you can boil water in. You might run out of chemicals or they might not kill the bugs in your locale, but boiling does the trick-- that and some careful handling so you don't cross contaminate.

"
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Well said.

The marketing machine has brainwashed people into thinking they need virus protection when they dont on this continent for the most part. Water is too cold to harbor viruses.

Chlorine dioxide is still questionable for Crypto but it is rare anyway. I use many types depending on mood. Iodine is quick easy and cheap. Chlorine dioxide when I have it. Filtering is my fav as it takes the chunks out. Boiling when its convenient.

Agreed a pot is as important as a knife or more in a kit.

Skam
 
All said, you might just consider the source of water you are drinking. Avoid the 1" deep pool of water next to the abandoned oil refinery waste outlet and go a bit upstream. Most natural bodies of water outside urban areas are pretty safe to drink from after filtering or chemical treatment. Viruses and significant chemical contamination are quite rare and most outdoorspeople don't plan for chemical decontamination. And I've never heard of an actual case of illness due chemical contamination from a natural water supply. Doesn't mean it can't happen, but rare enough to put in the "if it happens, it happens" category.
 
nick-nack said:
it wouldnt be so if we stopped dumping crap in. LOL!
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To late for that Nick-nack. There are tin mines in England that the Romans worked and exhausted that supposedly still have toxins leaching from them. In North America and Australia, there are mines that have been played out for a hundred years or more, that still add heavy metals to the local water supply. Heck, there are places in VT where you shouldn't drink unfiltered well water becuase of metal contaminants trapped in the granite, so it isn't all our fault.

Humans. *shrugs* We might be the dominant life form, but there are days were I wonder how.
 
nothing, including distilling gets rid of many chemical contaminants. i would like to point out, given the option between a blade and a container to boil water in, I will always choose the container; I can always make shift a blade without too much effort, containers to but require much more work. In my honest opinion, blades are over rated in order of priorities.

Alan Halcon
 
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