A backpacking water filter is a definite must-have for wilderness travel, unless you’re willing to take the time to make a fire and boil all your water before you drink it. Being hit with dysentery while in the wilderness is no fun, and unfiltered, unboiled water should only be drunk in emergency. Although that water looks cold and clear, you don’t know how many dead animals have fallen into it just a little way up, or how much excrement has been mixed in over the water course.
So buy a backpacking water filter. You need something that is:
You also want to make sure your backpacking water filter can give adequate output for your backpacking expedition; if you’re going alone, that means for you, but if you’re going with two or three other people, you’ll want a backpacking water purifier that can produce enough water for two or three people in a reasonable amount of time.
What water filter is best for you? There are a wide variety of filters available to backpackers today. The cheaper models tend to have a very limited capacity and clog quickly; the more expensive models can usually be expected to deliver a high output over a longer time. Of course, the downside is, they are expensive.
If you’ve got a reasonable budget for this one favorite filter among outdoor enthusiasts is the Katadyn Pocket Water Microfilter. This filter weighs just less than half a pound—0.46 pounds, to be exact—and can filter up to 50,000 liters of water, depending on water quality: for average dirty water, figure at least 13,000 liters. It puts out about 1 quart per minute, so can provide adequate clean water for a backpacking team of up to four people.
No, it’s not cheap, but if you look into the cheaper water filters, you’ll find they need the actual filter part changed quite regularly. Those filter parts aren’t cheap, so you’ll be paying a regular ‘clean water fee’. With the Katadyn Pocket Water Microfilter, on the other hand, you should be able to get more than 10,000 liters of clean drinking water before you need to worry about anything. If, before that time, the muddy water you’ve been pumping clogs up your filter, just open it up and clean it out. When you buy the filter it’ll come with two cleaning pads that make that job easy.
Another favorite water purifier is the Steripen Adventurer. This isn’t a water filter per se, and the water won’t go through it; instead, it’s a water purifier that kills all the nasties with ultraviolet light. The benefit over the Katadyn is that this purifier attacks viruses as well as bacteria and protozoans. The downside is that it won’t make muddy water any clearer, and doesn’t actually remove any extra particles from the water you’re going to drink—it just sterilizes them. The way it works is you put water in your container, dip in the pen, and let it do it’s thing: it’ll sterilize half a liter of water in 48 seconds. Magical, no? It does require batteries, and each battery is supposed to be good for 100 treatments. The UV lamp is rated as good for 8000 treatments. And the Steripen Adventuer is tiny and superlight: just 0.24 pounds, and 6.1 by 1.3 by 0.9 inches.
There are also cheaper possibilities, but make sure your backpacking water filter is reliable. You don’t want to be stuck with a piece of junk that breaks on the trail.