Tactical Tuesday presents: Water, Filters vs. Purifiers

[Mags]

Murph, Lundin has this in his book, "When All Hell Breaks Loose!" Pitch'em up on the roof and let BOB do the work. Guess I'd opt for this after I filtered best I could, sans modern equipment or chemicals. Always like learning and having options.

[Murph]

Murph, Lundin has this in his book, "When All Hell Breaks Loose!" Pitch'em up on the roof and let BOB do the work. Guess I'd opt for this after I filtered best I could, sans modern equipment or chemicals. Always like learning and having options.

I need to get my hands on his books. It seems like I keep seeing more and more things referenced back to them. And I agree with you about filtering out as much crude first as you can, no one likes chewing their water.

[olbaid_dratsab]

Do you think the process can be made quicker or more reliable by placing a mirror under the bottles? Or possibly putting a lense above that would magnify the light or concentrate it?

[Murph]

Do you think the process can be made quicker or more reliable by placing a mirror under the bottles? Or possibly putting a lense above that would magnify the light or concentrate it?

Maybe a mirror under the bottle. Using a lense I would imagine there's a chance you could melt the bottles.

[Mags]

Don't forget Platy's are clear too. Fill'em and lay'em out in the sun.

[ForgeCorvus]

If you're going to use the sun as your UV source make sure your container is clear, a blue tinted bottle shows blue because it is reflecting the blue end of the spectrum and you don't want that

[Weasel@ZS]

I've always been dubious about the effectiveness SODIS method but it seems perfect for a serious shtf / bugging-in situations and even having a clear bottle slung on your pack when you're walking might work.

Not sure about platypus bags though, they're clear but so is polycarbonate and UV doesn't go through that. They're made of urethane and polyethylene film, does anyone whether that's UV transparent?

I imagine SODIS wouldn't work with polycarbonate bottles either so that's something to be aware of.

[KnightoftheRoc]

I've never heard of polycarbonate having a UV filtering property- do you have a link to a source on that? I'm not disputing the claim, just curious about it. Seeing the popularity of the material, it would be a very valid concern.

On the SODIS topic- if you are lacking a mirror, try laying out a space blanket instead? It's not as efficient as a mirror, but it would beat having nothing. Keeping it folded to no larger than needed would probably help, too. BTW- UV water treatment tubes DEPEND on a highly reflective interior of the tube housing for just this purpose- if the UV rays don't kill something on the way in, maybe it will on the way out- or the next 8 gazillion passes it makes. Sooner or later, it's gotta hit something.

[Weasel@ZS]

It's just what I've heard when looking for glasses and oh so reliable wikipedia agrees with me

http://www.allaboutvision.com/lenses/polycarb.htm
http://en.wikipedia.org/wiki/Ultraviolet#Eye

[KnightoftheRoc]

It's just what I've heard when looking for glasses and oh so reliable wikipedia agrees with me

http://www.allaboutvision.com/lenses/polycarb.htm
http://en.wikipedia.org/wiki/Ultraviolet#Eye

I'd heard of UV protection being included in the eyeglasses, but I'd figured it was a treatment done to the lenses. I'll have to look into this one- it has me curious now.

[ForgeCorvus]

Not sure about platypus bags though, they're clear but so is polycarbonate and UV doesn't go through that. They're made of urethane and polyethylene film, does anyone whether that's UV transparent?

I work at a plastics place, I'll ask

[mattdcknsn]

One thing to note about bleach, it looses it effectiveness relatively quickly once opened. I found this quote but no direct source from a bleach company:

Consulting a Chlorox bleach representative produced this statement:

“We recommend storing our bleach at room temperatures. It can be stored for about 6 months at temperatures between 50 and 70 degrees Fahrenheit. After this time, bleach will be begin to degrade at a rate of 20% each year until totally degraded to salt and water. Storing at temperatures much higher than 70 degrees Fahrenheit could cause the bleach to lose its effectiveness and degrade more rapidly. However, if you require 6% sodium hypochlorite, you should change your supply every 3 months.”

I have heard of using pool chlorine tablets to make bleach at home. They last longer than bottle bleach.

Here's another goody I found the other day. Quick reference chart for bleach:

[Murph]

Good catch, mattdcknsn!
All chemical methods are prone to expiration dates.

[spacecase0]

be careful with the dry bleach for pools,
some of it breaks down to a salt that is not good for people

[maldon007]

I have heard of using pool chlorine tablets to make bleach at home. They last longer than bottle bleach.

Makes sense, probably 100 times cheaper, per oz. than the same dry chemical with a "water purification" sticker on the bottle. And you dont have to worry about liquid spilling all over your gear, in your bob.

...googling to find conversion chart from liquid, to solid tab.


Also, SODIS sounds good... but viruses were mentioned, and SODIS doesnt seem to claim to kill those (unless I missed that). How prevalent are dangerous viruses in ground water, runoff, etc?



Oh yeah, this homemade filter seems like a cheap/effective and sturdy filter, when used with chemical treating, or maybe with SODIS to help flavor and remove heavy metals and such.
http://www.youtube.com/watch?v=m8VQk4isaOM

[mattdcknsn]

Do you know Which ones do break down? Or a way to distinguish between the two?

be careful with the dry bleach for pools,
some of it breaks down to a salt that is not good for people

[KnightoftheRoc]

I have heard of using pool chlorine tablets to make bleach at home. They last longer than bottle bleach.

Makes sense, probably 100 times cheaper, per oz. than the same dry chemical with a "water purification" sticker on the bottle. And you dont have to worry about liquid spilling all over your gear, in your bob.

...googling to find conversion chart from liquid, to solid tab.


Also, SODIS sounds good... but viruses were mentioned, and SODIS doesnt seem to claim to kill those (unless I missed that). How prevalent are dangerous viruses in ground water, runoff, etc?



Oh yeah, this homemade filter seems like a cheap/effective and sturdy filter, when used with chemical treating, or maybe with SODIS to help flavor and remove heavy metals and such.
http://www.youtube.com/watch?v=m8VQk4isaOM

I'm not an expert on the viruses end of things, but I have installed wells and had to upgrade systems on wells quite a bit as a plumber. E.Coli is one nasty little bugger that can show up in wells, and something I've seen most often in wells near horse farms. Some of these wells were DEEP, too. So, yes, there are nasties that can get into, and travel with, ground water. For places with these problems, I've installed UV lights, and in some cases, chlorinators, to deal with them. No matter what is wrong with your well's water, there's a way to treat it, but some of them are so expensive that moving would be a lot cheaper than staying.
While I'm sure that sunlight, and it's UV light, WILL render water safe of creepy crawly nasties, what I'm concerned about is knowing how badly the water is contaminated in the first place- it isn't like most viruses can be seen with your Wal-Mart grade microscope, and really, who has the room to pack all this lab stuff in a pack? So, to me, it seems like a certain amount of faith is needed to decide when the water has had enough UV from sunlight on a given day. I remember one well we had to pull for a replacement, that had such a bad E.Coli problem, the well lines were coated nearly a half an inch thick in slime- apparently, the E. Coli. Needless to say, handwashing was done after that job at the first gas station we hit, and followed up with rubbing alcohol as a rinse, which we bought at the same station- there was no way I wanted to be taking any of THAT stuff home. We were lucky, no one got sick afterward, but a single rub of an eye or something like that could have gotten that crap into our systems.

[dan1775]

Thanks for this great information.

I'm still confused about one (rather large) point: What about non-organic chemical contaminants? Most of the information here and elsewhere pertains to filtering out/killing harmful microorganisms. That still leaves me uninformed on a few points:

What compounds/elements commonly found in North American waters can be harmful to ingest (if any)?

Are there bodies of water particularly likely to be contaminated with such? For example, should one avoid water found in industrial areas?

Short of distillation, what measures can be taken to make such water potable?

Thanks!

[Murph]

I think there are a few threads about dealing with chemical contaminants. You'd have to search for them. I can't say I could offer a lot of insight to the issue.

[maldon007]

As for chemical contamination, it seems like a activated carbon filter would be a fast/cheap option, maybe like the one I posted above?

I know carbon absorbs lots of chemicals from air (as in gas mask filters)...

Here is a chart that is supposed to show absorption potentials of activated carbon-

http://www.sentryair.com/activated-carbon-filter.htm

...Of course this was for air filtering, not sure if water filtering is exactly the same.

[raptor]

I would point out that there is a Hall of Fame post with a lot of good information on water filtration and what to do when the water turns off.


viewtopic.php?f=89&t=53446

[Murph]

I would point out that there is a Hall of Fame post with a lot of good information on water filtration and what to do when the water turns off.


viewtopic.php?f=89&t=53446

Yup, that is a good one. Consider this the backwoods edition of it.

[Tireur]

I'm still confused about one (rather large) point: What about non-organic chemical contaminants?

Screwed.
Heck, even most municipal water treatment plants can't remove the majority of chemicals in the system. Their solution is to simply stop testing for them, awesome eh?

The OP seems to have glossed over a major point, the difference a filter and a purifier is that a purifier kills as many beasties as it can while a filter removes them. Filters are better, purifiers are more portable; in really nasty swamp water use both. Something to think about, even dead bacteria can pose a threat if your system is already compromised.

The most miserable time I ever had in the woods was when I was silly enough to head off into the bush while I was still suffering from a salmonella attack (ugh, stay away from the Eggs Benedict at the brunch buffet). Even though all my water thoroughly boiled Giardia spores can still be viable if given a suitably wasted immune system to take root in. A week of backwoods Beaver Fever shooting out of both ends (occasionally simultaneously) was a fun time and ever since I've taken a filter.

And pumping sucks, go gravity filter. Filters a gallon in a few minutes.

[spacecase0]

Do you know Which ones do break down? Or a way to distinguish between the two?

be careful with the dry bleach for pools,
some of it breaks down to a salt that is not good for people

I have looked some at this,
and I really can't figure it out...
the regular liquid bleach (sodium hypochlorite) breaks down to regular salt (sodium chloride)
the powdered calcium hypochlorite is also good as it breaks down into calcium chloride, and that is not that bad...
but I would still rather have sodium chloride, but the liquid really does degrade to fast.

I have seen others on the market with strange ingredients, stay away from them

also just found this
http://www.survivaltopics.com/survival/ ... ect-water/