I am a microbiologist by training and therefore have a healthy respect for getting horrendously sick from the water. We hike in the Ozarks and that means pretty much everywhere you go there are houses on septic tanks upstream from where you are. We have livestock that drink from streams. As we do not live where there are pristine alpine streams, we opt to treat our water. Obsessively. I had Giardia as a child and it was not nice. I do not care to repeat that.
The MSR Sweetwater is a pump filter that has a ceramic filter which removes protozoa, cysts, and bacteria and a carbon filter which neutralizes bad tastes. After we pump the water we treat it with chlorine drops to kill viruses. It’s a bit fussy to use with all the hoses and connections. And it will make your arms feel like they are falling off by the time you’ve pumped six liters. Especially when standing in icy water, bending over holding an increasingly heavy water bag. But we’ve checked the alternatives and we’re sticking with this for now.
We carry water in an MSR Dromedary. We have the 6 liter size. We find that most of the time the two of us use most of the six liters per day. I love the Dromedary. The Sweetwater filter has a fitting that screws directly onto the Dromedary. The bag itself is durable, not terribly heavy, and often spends its nights under the head end of my sleeping pad. After dealing with leaky hydration bladders I was skeptical about depending on this bag, but it seems to be bulletproof. The rough Ozarks creek stones don’t even faze it.
You can purchase the MSR Dromedary, MSR Sweetwater purification filter and supplies from our Backpacking Store