Best Water Filters for the Appalachian Trail in 2019


An essential piece of any thru-hiker’s kit is a reliable water filter. There are many, many water sources available along the Appalachian Trail but not all are safe to drink from so it is highly recommended that all hikers treat their water each and every time before taking a sip. While there are literally hundreds of options and features to consider when finding the ideal filter for your trip, there are not many filters that fit the bill for a long-distance hike.

Below I have outlined the three top choices for lightweight, practical, and affordable water filters for any long-distance hike.

Sawyer Squeeze

  • MSRP: 49.95 
  • 3oz
  • Flow rate: 1.7 liters/minute

The Sawyer Squeeze is one of the most popular and recognizable filters on any trail. Its ease of use, relatively low weight, and ability to attach directly to Smart water bottles makes it an ideal thru-hiking product. It’s also rated for 1 million gallons of through-put – one of the highest on the market. However, despite its bountiful advantages, there are a couple of significant drawbacks to the Squeeze filter that you may wish to consider when researching filters for your thru-hike.

One major drawback of the Squeeze is the durability and usability of the collection bags. These bags are rigid, poor quality, and have small openings which make it difficult to collect water when a source isn’t running well (which is more often than not, it seems). Hikers go through several of these bags during their thru-hike and the cost of additional bags can really start to add up. I saw several hikers on the trail get around this by purchasing a Platypus “Platy” 2L soft bottle which can thread directly into the Squeeze and is much more durable than the bags included. However, the opening of the Platy bottle isn’t any larger so it doesn’t fix the collection issue and it also incurs an additional cost and weight as each 2L bag retails for $12.95 and weighs 1.3oz.

A second drawback of the Squeeze filter is that its ceramic core is susceptible to damage if it freezes. If you’re hiking on the Appalachian Trail in the Spring it’s very likely you’ll encounter many below-freezing nights and if you don’t take care of your filter (by putting it in your sleeping bag when you go to bed) then you’ll wake up with a useless hunk of garbage. What’s more, the filter tends to clog more and more as its used and the flow rate steadily decreases to just a trickle.

Overall, the Sawyer Squeeze is a solid choice for a filter that will likely work very well for your hike as it has for thousands of others. Just know that it has some drawbacks and that the $49.95 price tag isn’t the end of your expenditure when going with this model.

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Katadyn BeFree 1.0L

  • MSRP: $44.95
  • Weight: 2oz
  • Flow rate: 2 liters/minute

The BeFree filter made a splash on the long-distance hiking scene in 2018 (pardon the pun). At that time, the only real choice for a lightweight water filter was the Squeeze, and Katadyn directly targeted the market to bring something that was lighter and faster than the competition. After seeing lots of good reviews for the device, I decided to take one with me on my thru-hike and see how it fared.

My honest review is that it hit all the marks in the beginning but performance degraded quickly and significantly. At first, the flow rate was impressive and I was stoked that I could keep it in my hipbelt pocket and filter on the go without even having to take off my pack. Also, the wide-mouth Hydrapak flask makes it super easy and fast to fill from water sources when others with Sawyer bags needed a separate scoop.

However, as time went on the filter got more and more clogged (despite my attempts to clear) and the flask began to tear. By the time I got to Maine it was taking 15 minutes or more to filter a liter of water, which nearly brought me to tears with frustration at times when the mosquitoes were absolutely relentless and I just wanted to get inside my tent. So although the filter did actually last my entire thru-hike, it was practically useless by the end. I returned it to REI for a refund as it did not meet the manufacturer’s claims of 1,000 liters of through-put.

Despite these shortcomings, the BeFree could still be a good choice for some hikers. It’s relatively inexpensive to purchase, and if you buy from a place like REI you can simply return it for a full refund if it fails prematurely. It’s also the lightest filter system currently available and is collapsable down to just the size of the filter (about 3″) for easy storage. This could also be a great option if you’re not planning to do a full thru-hike and want something easy to take on day trips or short travel.

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SteriPEN Ultra

  • MSRP: $99.95
  • 4.96oz
  • 90 seconds/liter

On the surface, the SteriPEN seems to be the worst device on the list as it is more expensive, heavier, and slower than the other two options. However, it’s still an option worth considering when you have a look at its features. The SteriPEN has an internal lithium battery that is rechargeable via USB and lasts long enough to treat 50 gallons of water on a single charge. Its screen clearly indicates when your treatment is successful and the water is safe to drink, how much battery life is remaining, and how many treatments the device has been used for. The lifespan of a SteriPEN, according to the manufacturer, is about 8,000 liters – meaning it will last far longer than a traditional thru-hike. What’s more, if you actually use all 8,000 liters, SteriPEN will send you a brand new device for free.

The downsides of a SteriPEN, as mentioned, is its price, weight, and speed. Costing almost twice as much as a Squeeze and weighing twice as much as the BeFree is a bit disconcerting. It also doesn’t filter out any sediments or dirt that may be floating in your source (it treats the water with a UV light to eliminate over 99.9% of bacteria, viruses and protozoa that cause water-borne illness). What’s more, you’re limited to treating one liter at a time which can add up if you’re hiking with multiple people.

Despite these shortcomings, what the SteriPEN lacks in affordability it makes up for in quality. In my experience, the effectiveness (e.g. flow rate) of squeeze or pump filters degrades over time to the point where they are hardly usable or require replacement parts. You won’t have any of these problems with a SteriPEN, however, as it takes just as long to sterilize a liter of water on its first cycle as it does on its last without any squeezing, pumping, clogging, or flushing. All in all, I have seen and heard great things about the SteriPEN and will strongly consider picking one up for future travel and hiking trips.

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Honorable Mention:

Sawyer Squeeze Micro ($27.95) – new addition to the Sawyer lineup for 2019 which boasts a smaller profile, lighter weight, and more durable collection bag than the original Squeeze. Definitely something to consider!


The three water filters mentioned here are by far the most popular choices for long-distance hikers on the AT, PCT, and CDT. Each device has its own positive features and negative drawbacks which make them unique. If your goal is to only thru-hike one of the long-distance trails, cost is a factor, and you can make sure the filter doesn’t freeze, then the Sawyer Squeeze (or the Squeeze Micro) is your best bet for a tried-and-true filter. If weight is your ultimate concern then you might look closer at the BeFree (just be aware of the shortcomings I mentioned above). However, if you plan to do more extensive backpacking, worldwide travel, and are more concerned with quality than price, I suggest picking up a SteriPEN as it will likely outlast most conventional filters by a large margin and provide faster through-put (once the filters get helplessly clogged) for a longer duration.



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