Is a million gallons long-term enough for your water purification needs? LOL

And it filters out viruses to boot...

I've been looking at Sawyer Water Filters for quite a while now, and recently they added the Sawyer Complete Water Purifier Sytem: Viral (SP194) to their lineup.

.02 Micron Absolute Filter
Gravity Fed
Viral Filtration to 99.9997% (>5.5 log)
Biological Filtration to 99.99999% (7 log) bacteria and 99.9999% (6 log) protozoa
1 Million Gallon Guarantee

I'd still put an activated carbon cartridge backup on it for chemical filtration, but otherwise this system looks great.

the 4 Liter setup runs about $140.00 at Bass Pro Shops.

That's a lot cheaper than a Big Berkey and more portable, too. Not as durable though, but that's okay.

-Blast

How about The Sawyer Bucket Kit then?

OK, I have to admit I'm wanting these. .02 is pretty good.

I got one of the bottle viral units and was somewhat disappointed. It took a long time to prime, and the flow rate was never good, even after running for a few hours. Haven't used it in practice, but I'd hate to have to prime it in a disaster situation. Now, the bag arrangement may be better, where you can hang it up and leave it for a while.

Good to know.

Thanks for the hands on information!

Beware putting all your eggs in one basket.

I would rather have three smaller filters than one really big one. Things can and do go wrong. having several smaller ones means they are more portable and allow you to use them at multiple locations.

The actual filter part for the setups being discussed are fairly small, less than the size of an average soda can, so you could pack a few of them if you felt the need.

I already have one filter in my BOB, so this as an addition could only add to my setup, and it's actually smaller than my current filter.

On Sawyer's website a video for the bucket setup claims the filter can purify 5 gallons in less than 20 minutes.

Does that sound about right?

EDIT:

Upon further research, the filtering time above is not for the viral filter, but rather the biological filter only. The time they quote for the viral filter is 4 liters in about 15 minutes.

Does this sound similar to the flow rate you were getting?

Thanks for any information.

Boiling it, for zero minutes, remains the surest way to eliminate pathogens.

Oops, boiling it for zero minutes won't eliminate any pathogens.

I think you need to boil water for at least a few minutes to get rid of most pathogens.

I think the moment that the water reaches its boiling point, technically whatever you're trying to kill is dead. The reason you're told to boil it is just so there's no guessing if the water is hot enough... If I recall correctly...

I read that in an thread here in the forums. Can anyone back this up, or have I lost my marbles?

In any case, I'd probably let it go for a couple of minutes at a boil because I'm paranoid.

Water must be boiled vigorously for at least a minute to get rid of giardia and cryptosporidium would probably take longer. Most other pathogens (fecal coliform, ameobas, viruses) are destroyed after a shorter period, but if you've ever had a case of giardiasis, as I have, you will gladly boil that water for the full minute, and maybe then some.

Now then,

I was taught several different theories. Latest news it that once it is at a "roiling boil" that is enough.

But like Benjammin said it only takes one sample of giardiasis to convince ME that the small amount of extra time really couldn't hurt.

I quote my information as provided by the US EPA, and a host of other online official sources. One minute at hard boil seemed to be the SOP recommendation.

If you can get the water to a boil, keeping it there for a minuts shouldn't be much more of a challenge.

That's pretty much right. Also, at lower temperatures it takes longer. By the time it's reached boiling, the water will be both hot enough and for long enough. The EPA etc tend to give very conservative guidelines for obvious reasons.

Here's a link:
http://www.marinemedical.com/articles/water.htm

I found other links that say Giardia is killed at 135°F (57°C) and Cryptosporidiosis is killed at 149°F (65°C) (presumably it takes at least a minute).

Some of these recommendation probably are to take in the effects of altitude.

I live at 6000 ft and water boils somewhere around 200 F. If you were a backpacker
at 13000 ft in the Sierra or Colorado, the temperature for boiling would be quite
a bit lower than that.


http://www.csgnetwork.com/h2oboilcalc.html

I'm telling ya, ya wants to boils that dust-speck a while or it'll git ya!

This is one of those ounce of prevention=several kilos worth of cure kinda precautions.

Better to overboil it and not need it, than to underboil it and get a parasitic infection.

Don't say I didn't warn ya. Been there, done that, don't ever want to do it again. The EPA guideline ain't that conservative, more of a minimum.

I have to agree with 'benjammin' on this one.. dont care what the minimum is... i have had Giardia.. and let me tell you that you do not want it.. it wipes you out.. and you will be worthless to everyone.. just boil it good and hard if thats the way your gonna kill the stuff...Dont take the chance..!!