Water filter hydration pak

I tried a hydration pak for the first time a few weeks ago in Mexico. I was surprised at how much I liked it. I had carried a gravity-fed water filter as backup and had less than ideal results when I needed it, so I researched a little more when I got home. Several of the back-packing forums described using an in-line filter in the hydra pak. I decided to try it and so far it seems to work very well.
Here is the filter I purchased,

from Walmart, $34:
http://www.walmart.com/ip/Sawyer-Inline-Water-Filter-with-34-Ounce-Bottle/8283710
The hydra pak is also from Wally-world, off the shelf, $20

and installed:

This same filter is available from Sawyer in a kit intended for use on a hydra pak, but the only retailers I could find wanted ten bucks more for it without the bottle.

I've got a Sawyer, used it backpacking a couple of times. Bought it because unlike every other purifier out there, there is no cartridge that needs to be replaced - just backflush with known good water.

How effective is the filter are there any specs?? I pack a Katadyn hand pump water filter that has these specs.

Weight 11 oz.
Size 6.5 in. x 2.375 in.
Removes bacteria, protozoa, giardia
Pore Size .2
Pump Strokes/L -
Cart Capacity 200 gal.
Liters per Minute 1 L/min.

Click to expand...

I've pumped water out of the Rio Grande with it while in Big Bend and didn't get sick with it lol. But an inline filter would be more convenient, just pour in and drink.

Since installing the filter, I have used the pak on two trips but I have not had the need to refill in the field. The filter does add a little bit of resistance, not enough to worry about. It does work very well. Here are the filter specs from the sellers site:

Sawyer Inline Water Filter with 34-Ounce Bottle:
0.1 micron absolute hollow fiber membrane inline filter
Highest removal (99.99999%) of bacteria, cysts and protozoa
Also filters out sediment and other contaminants
Ensures that water meets EPA and WHO recommended levels
No iodine required
No pumping or chemicals
More effective than pump filters and more convenient
Removes the following contaminants:
Cholera
Botulism (Clostridium batulinum)
Typhoid (Salmonella typhi)
Amoebic Dysentery
E. Coli, Coliform Bacteria
Streptococcus
Salmonella
Giardia
Cryptosporidium

Since I put this one together I was told of another complete filter-hydrapak system being sold by an inmate at ADV. His pak looks very good, but is considerably more expensive, ranging from $49 for just the bag and filter to fit your pak, to $110+shipping and up for a complete system.Geigerrig
As far as I can see the Geigerrig's best features are the easy-cleaning and the warranty. As expensive as it though, I'll keep using my cheapie. I may not own one anymore but I still like KLRs, too.
John

**** that little thing filters 1 micron better than mine. I may have to look into this.

Some quick water purification basics:

In order of decreasing size, biological threats in water include 1) cysts / parasites, 2) bacteria, and 3) viruses.

Cysts, being relatively large, are easy to physically filter out. Some can be tough and resistant to chemical sterilization.

Bacteria can be physically filtered out by the right kind of device; also many (but apparently not all) are vulnerable to chemicals.

Viruses, being very tiny, are tough to physically remove, but there are now products that can do so. Viruses are vulnerable to chemicals.

For more reading, visit http://www.high-altitude-medicine.com/water.html - has lots of details on how to use various kinds of iodine and chlorine to maximum effect; very useful if you live in an area at risk of disasters. Note that this page is out-of-date as there are now devices that can physically remove viruses.

Used to be, there were two ways you could ensure to get *everything* biological out of water:
1) bring it to a boil
2) run it through a filter to get the cysts and bacteria, then disinfect (usually with iodine) to kill the viruses.

Nomenclature note: a 'filter' gets the cysts and bacteria, but not the viruses. A 'purifier' gets all three. At least that's how I remember the terms being used in the research I did online a couple years back. My memory may be faulty. Please do your own research to verify everything I'm saying, as your health is at stake here!

Sawyer has two grades of devices - one will remove cysts and bacteria, but not viruses; their higher grade will remove all three. So now there's a third option. Also, there are UV sterilizers that kill everything (need batteries; expensive), and some super-duper purifiers that yank the cysts and bacteria with a filter and use silver to kill the viruses (expensive). IIRC (from the Sawyer demo person who was at REI while I worked there), the higher grade has a slower flow rate, as you might imagine.

http://www.sawyer.com/products.htm

http://www.sawyer.com/biological.htm <-- page on their filter, the .1 micron one that gets cysts and bacteria but not viruses. If you think viruses might be a threat (depends on geographic location), iodine IS required to kill them.

http://www.sawyer.com/viral.htm <-- page on their purifier, .02 micron, which gets everything.


Sawyer filters/purifiers have various configurations; think about how you want to use the system before you buy it (suck straight out of a bottle? Gravity-powered inline drip, which necessitates two containers? Option of doing both?). If I sound like I'm pushing Sawyer, it's because I'm budget-minded and Sawyer had the cheapest filters - with no cartridge replacement necessary - that I could find at the time.

If you want to pull out hazardous chemicals (like from ag runoff) or heavy metals (if you're in or downstream of an area that was mined), you'll need an activated carbon filter.

And, all this stuff works better (clogs a lot slower) if you filter out the larger stuff using a coffee filter, bandanna, or something similar first.