With the right gear, you can run without lugging around pounds of water. Combined with their new hydration pack adapters, Sawyer’s Squeeze Water Filter ($40) allows you to drink clean water while training in the backcountry. The extra hardware added a mere 3 ounces to the hydration pack and let me drink through the bite valve without hassle.
Despite its small size, the filter is rated for over a million gallons of dirty water and removes bacteria, such as salmonella, cholera and E.coli, as well as with protozoa, such as giardia and cryptosporidium. It does not remove viruses (though you’re unlikely to encounter these outside populated areas).
To set it up, I cut the bite valve hose close to the reservoir. I pushed the Inline Hydration Pack Adapters ($5) onto the hose ends and screwed the filter on tight. During the run, I filled the reservoir with water from a stream. Then the dirty (or suspect) water went through the filter before it reached me.
If you're wary about adding dirty water to your pack, the alternative is Sawyer’s Fast Fill kit ($9), which I also tried. You add dirty water to a supplied 32-ounce squeeze pouch, then squirt it into your hydration reservoir. You unclip the filter, store the filter and squeeze pouch, and drink directly from your hydration pack.
I liked the inline product better, even though it required adding dirty water to a hydration reservoir. It presented less hassle and delay. In my arrangement, it was easy enough to remove the reservoir to replenish water from a stream. And that way, I didn’t have to carry a squeeze pouch, or wait while filtered water trickled into the bag.
Using the filter meant pulling a little harder on the valve to drink, but the extra resistance incidentally helps regulate the flow during hard exertion.
The kits work with most hydration systems, including my Platypus bag, though I hear they don't work with Osprey products. In that case, you could probably find an adapter for a few dollars in the PVC tubing isles of a big box hardware store.