The 7 Best Backpacking Water Filters
These filtration systems will keep you from becoming high and dry in the backcountry.
A reliable water filter is a must, at least if you like your drink without a side of giardia. There are innumerable devices on the market these days, with microfiber filters coming in all shapes and sizes to squeeze, suck, press, or drain your dirty backcountry sources into safe-to-drink water. We’ve tested enough filters to fill hundreds of Nalgenes with clean water, and learned a few things along the way to help you shop for the perfect one.
What to Look For in a Water Filter
Water Filter Designs
Thru-hikers and ultralighters tend to lean on light and compact straw and bottle filter systems like the Sawyer Squeeze, which weigh just a few ounces and won’t break the bank. Some lightweight filters can be rigged as “in-line” filters, which attach to the tube between your hydration reservoir and mouthpiece, making water stops even speedier. Gravity and pump filters can require less effort than squeeze and suck systems when filtering large amounts of water, but contribute to pack weight, size, and cost. Note: Chemical tablets, drops, and UV devices are not included in this list.
Filter Cartridge Types
Every filter uses a central element to do the heavy-lifting: a cylindrical core with small holes to trap debris. The most common types are ceramic filters and hollow fiber filters, effective at removing most harmful contaminants.
Hollow fiber microfilters are a bundle of tiny tubes, each typically covered in 0.2 micron pores. These weigh less than ceramic and have a larger surface area for faster filtration, but the delicate fibers inside require regular backflushing and are prone to freezing—a death sentence for most cartridges. Ceramic filters, using a solid core with pores, come at a similar price point as hollow fiber and offer a comparable filter quality. They can be easily cleaned with backflushing or brushing on the trail (though they’re still susceptible to freezing.) Some filters also include activated carbon for its ability to absorb and remove tastes and odors from water.
September 24, 2021