Water Filters and Bladder
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Katadyn BeFree
(Amazon Link)
Price- $29.95
Weight- 1.6 oz
Our standard filter for many years, spanning thousands of miles hiked and hundreds of days in the wilderness. It has 42mm threads, so it fits perfectly on HydraPak water bladders (our preferred kind).
It uses hollow carbon nanotube filaments with a pore size of 0.1 micron, removing 99.9999% of bacteria and 99.99% of protozoa (like giardia). That's enough nine's for me to feel safe and we've never had issues with waterborne illnesses using this filter, even in livestock impacted areas.
The speed and ease of filtration with the BeFree have made this a favorite staple in our kit despite its biggest weakness, sediment. Yes, this filter can clog suddenly but Bugs has perfected a technique to restore the flow rate that works most of the time. She fills the bladder maybe a third full with clear water, threads on the filter and then she shakes the bag, violently. This has proven to be surprising effective but it doesn't always work...
The Good- It is incredibly fast, filtering about one liter of water per minute (or even a bit more when the filter is brand new). It lasts for dozens of weekend trips or roughly 500–700 miles on a thru-hike filtering water for two (with pristine water).
The Bad- You have to be very selective with your water sources. Less-than-prime sources with heavy silt or sediment can reduce the flow drastically and sometimes irreversibly. For this reason, when we're hiking in the desert or areas with murky water, we always carry a secondary filter of a different type (See the Sawyer Squeeze below).
(used by Moose near Karakol Peak in eastern Kyrgyzstan)
Sawyer Squeeze
(Amazon Link)
Price- $45.95
Weight- 3.0 oz
If you want a filter that is light, small, and supremely reliable, this is it. With standard 28mm threads, it will fit right onto standard SmartWater bottles or a wide variety of water bladders.
This is another hollow carbon nanotube filter, but I Sawyer states they use thicker walled tubes, allowing for almost endless backflashing without damaging the integrity of the tubes. This allows you to restore the flow rate over and over again, even after filtering some gnarly water, like from a cattle pond in New Mexico.
It isn't the sexiest piece of gear, but it's tried and true and has never failed on me.
The Good- It handles silty and sediment loaded water remarkably well. When you need to filter water that looks like chocolate milk and expect your filter to keep working, this is the tool to use. You can backflush it repeatedly to restore a functioning flow rate, and Sawyer claims a ridiculous operational lifespan of up to 100,000 gallons.
The Bad- It is slow and can be painful to manually squeeze water through. To get around this, when we need to filter large quantities, I prefer to hang my bladder and let gravity do the heavy lifting.
(below- the aforementioned cattle pond in New Mexico on the Grand Enchantment Trail)
Above- I'll let this photo do the talking and demonstrate the versatility of the Hydrapak Seeker bladder with a Sawyer Squeeze filter used creatively to gravity filter a few liters of water in a treeless expanse in the Gegham Mountains in Armenia. Spring 2025.
Katadyn Steripen Ultra
(Amazon Link)
Price- $135.95
Weight- 4.9 oz
This was a new addition to our kit in 2025 before we left the United States for our long international adventure. While we didn't carry it on our hike of the Transcaucasian Trail in Georgia and Armenia, we have used it several times since, especially in the subtropical and tropical regions of Southeast Asia where ground water tends to be warmer and there could potentially be a risk of viruses. We also used it in areas where we knew there were monkeys, as I think they can spread zoonotic viruses but I honestly haven’t done a deep dive into how likely that is through shared water sources, but with UV sterilization we’re safe either way.
The Good- It is incredibly easy to use and has worked well for us even in colder conditions, like at nearly 12,000 feet in Taiwan. It's a great peace-of-mind layer if you have any concerns about viral contamination, which standard hollow-fiber carbon nanotube filters cannot remove.
Its also a solid stand alone filter if your water conditions are right (i.e. very clear).
The Bad- The internal battery yields around 50 liters per charge (though we got slightly fewer liters in real-world conditions), meaning you have to manage your power levels on longer trips.
More concerning, we have had several instances where the UV light activated before it was inserted into water. This is supposed to be prevented by two small electrodes that act as a kill switch and won’t allow the bulb to turn on and turn it off if it's not submerged. This raises some concerns about the performance of the electrical components as a whole.
Finally, it also won't filter out physical floaties or sediment from murky water, so prefiltration is necessary if you don’t have clear water.
(Seen here being used by Bugs to purify water on the North 2 Route in Taiwan.)
HydraPak Seeker 3L or 4L
Price- $30.00 - $33.00
Weight- 3.2 oz (3L) / 3.7 oz (4L)
This bladder has impressed us with its durability over and over again. I have only replaced our bladders one time, and that's after literally thousands of miles, hundreds of nights of use, and hundreds of gallons of water carried—especially during our trek of the Hayduke. When backpacking in remote desert areas where your life can depend on your water carry capacity, it's a piece of gear I trust.
The Good- Bombproof resilience that handles heavy trail abuse beautifully. It features 42mm threads that natively fit the BeFree filter and HydraPak’s own filter cap. It also sets up easily as a gravity filter bag or can be adapted to couple with a Sawyer Squeeze using quick-connect fittings (my go-to desert setup).
The Bad- It is a few ounces heavier than the lightest bladders on the market, though the durability more than compensates for the minor weight penalty.
There is a faint plastic taste from the bladders, especially when new or after storage. This doesn’t bother us but some people may be more affected, at least according to reviews I've read. Personally I can’t stand strong plastic tasting water so I’m not sure why this happens to some people.
Hydrapak 42mm Filter Cap
This filter has very similar performance to other carbon nanotube filters. The pore size is slightly larger and this increases the flow rate a tiny amount. It's a very fast and easy to use filter when water conditions are good (low turbidity). You can filter 4 liters of water without forearm cramps and too many curse words. It's susceptible to the same failures as similarly constructed filters, like rapid clogging in sediment rich water, but that comes as no surprise. Shaking it with a little water in your bag can clean the filter and restore some flow but in my experience when they fail significantly you never can restore any real amount of filter speed.
But again, despite those issues, if I'm going to have water of reliable quality with low sediment I use this filter for its speed and simplicity.
CNOC Bladder 3L VectoX
I love the design, its wide zipper opening allows you to fill your bladder directly in a low flow source, shallow stream, or pond. This is very challenging with a traditional bladder without a "scoop" or stirring up a lot of sediment. Unfortunately, I've had these fail on me in a number of ways, including small punctures, cracked lids and splits in the neck of the bladder. The company has always worked with me and replaced the leaking bag but it makes me nervous that it could fail and leave me very short of water (and we had close calls). CNOC is constantly making improvements and I hope in the future some of these issue will be corrected because I love the design and its available with two thread sizes. For light use or in situations where a loss of a few liters of water isn't critical, I'd recommend this with caution.
