Best Backpacking Water Filters and Purifiers of 2025
The Top Water Filters for Backpacking, Bikepacking, Camping, Hiking, and Trail Running
April 10th, 2025, updated with a new winner, new models tested, and new testing notes on flow rate and back flushing
Clean drinking water is essential when you head into the backcountry, and an effective, reliable water filter or purifier ensures that you have it.
We’ve tested dozens of backpacking water filters and water purifiers over thousands of miles to find the best water filters for most outdoor adventures and international trips. And we really put them to the test on thru hikes such as the Oregon Desert Trail and Arizona Trail, where the water quality is questionable at best, for long-term data.
Whatever your use case is, we have a field-tested water filter or purifier for you. Whether you’re hiking solo or in a group, traveling internationally, trail running, bikepacking, or thru hiking, read more for our top choices.
Need someplace to store all of that clean water? We have guides for water bottles for hiking and water bottle holders for biking.
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Comparison Table
| WATER FILTER | TREELINE AWARD | MSRP | WEIGHT (OZ)* | TYPE | SPEED | FILTER SIZE (μm = MICRONS) | REMOVES PROTOZOA & BACTERIA | REMOVES VIRUSES | REMOVES HEAVY METALS | REMOVES MICRO PLASTICS? | LIFETIME (L) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Platypus QuickDraw Filter | Best Overall Read why |
$40 | 2.9 | Squeeze filter | 3 L/min | 0.2 μm | 1,000 | ||||
| Sawyer Squeeze Filtration System with CNOC Bladder | Best for Thru Hiking Read why |
$65 | 3.0 | Squeeze / gravity filter | 1.7 L/min | 0.1 μm absolute | 3+ mil | ||||
| Platypus GravityWorks 4L | Best for Groups & Best Gravity Read why |
$135 | 11.5 | Gravity filter | 1.75 L/min | 0.2 μm | 1,500 | ||||
| MSR Guardian Purifier | Best for Removing Viruses Read why |
$400 | 17.3 | Hand pump purifier | 2.5 L/min | 0.02 μm | 10,000 | ||||
| Katadyn BeFree | Best for Short Trips Read why |
$45 | 2.3 | Squeeze filter | 2 L/min | 0.1 μm | 1,000 |
The Best Backpacking Water Filters
The Best Overall Backpacking Water Filter: Platypus Quickdraw
Weight: 2.9 oz
Type: Hollow fiber, squeeze
Liters per minute: 3
MSRP: $40
Removes microplastics? Not stated
Best for: Hikes and shorter backpacking trips, mountain runoff and streams, one person
What we liked: speed of flow, takes a long time to clog, ease of backflushing, dual caps prevent leaking and are attached so can’t lose them, integrity test indicator tells whether it is still functioning after a freezing night
What we didn't like: Cartridge only lasts 1000 L (250 gallons), doesn’t protect from viruses, squeezing can be tedious, requires cleaning with bleach before storing
The Platypus QuickDraw is an ultralight squeeze filtration system that is easy to use, portable, and durable. The filter lasts about 1,000 liters, which works out to $0.04 per liter. Due to some design features, it just edged out the Sawyer Squeeze as our Best Overall Water Filter.
Our testers have taken the QuickDraw on the thru-hikes of the Tahoe Rim Trail and the Grand Enchantment Trail and noted its impressive durability, ease of use and backflushing, and thoughtful design features.
Compare Prices of the Platypus Quickdraw Water Filter
For example, the filter has end caps on both sides to prevent leaking, which allows you to sleep with it on cold nights (to prevent freezing) without worrying it may leak in your bag. (You can read more about preventing your water filter from freezing and why it is crucial in our Shoulder Season Backpacking Gear guide or How to Prepare for Hiking in a Big Snow Year articles).
And if does freeze, the filter has an integrity test feature so you can ensure it is working before using it. Additionally, the cap to the QuickDraw is connected to the filter, which makes it one less piece to potentially lose.
Backflushing the QuickDraw in the backcountry is easy–you simply attach the dirty side to a partially full bladder and shake. This is important because, like the Sawyer Squeeze, the filter will slow down over time–especially after use in silty water, glacier melt, or other sources with more particulates.
Best water filter for thru hiking: Sawyer Squeeze System with CNOC Bladder
Weight: 3.0 ounces
Type: 0.1 micron absolute filter
Liters per Minute: 1.7
MSRP: $40.95
Removes microplastics? Yes
Best for: longer hikes or bikepacking trips, questionable water, one person
What we liked: Cost, weight, speed, warranty, donates 90% of profits to clean water
What we didn’t like: No way to test whether it is still working, must keep it above freezing at all times
After testing the Sawyer Squeeze over thousands of miles and dozens of different long-distance trails, it’s the best water filter for thru-hiking. From questionable desert sources to pristine alpine water, the Sawyer has never failed us. It’s light, reliable, fast, and easy to backflush in the field.
While other filters may have faster flows at the beginning, the Sawyer Squeeze is the one that is built to last a 2000+ mile thru-hike or bikepacking trip. And while other filters need replacement cartridges every 250 gallons, the Squeeze is good for a million gallons. This all means the Squeeze is the best for thru-hiking.
Compare Prices of the Sawyer Squeeze Water Filter
New for this year, the Squeeze comes with a dirty bag made by CNOC. We've been long-time fans of CNOC water bags for thru-hiking and think they are an excellent update to the Squeeze filter system. CNOC bags are more durable, easier to squeeze water bags than the old Sawyer bags or the bag that comes with the Platypus Quickdraw. You can still get the old original system, but it's a no-brainer to get the Squeeze x CNOC kit for less than the price of adding on a CNOC Vecto bag separately.
Our preferred method is to drink from our Squeeze straight through the sports top, getting our fix instantly. Alternatively, the Sawyer coupler (sold separately) makes it easy to convert the Squeeze to a gravity system between two CNOC bags or a CNOC bag and a bottle.
One difference between Sawyer and other filters is that it filters to 0.1 absolute microns. This is different from 0.1 nominal microns advertised by other brands, or 0.2 microns advertised on the Platypus Quickdraw. Absolute means that 99.9% of particulates 0.1 microns and up will be filtered out. Nominal (or average) microns have a less strict standard, meaning up to 20% variance in which pores can be larger.
As a result of the ability to filter to 0.1 nominal micron, we love that the Squeeze removes 100% of microplastics. One study concluded that “microplastic is frequently present in freshwaters and drinking water.” While the effects on human health of ingesting microplastics are still being studied, we like knowing that the Squeeze is removing them.
For more on the Sawyer Squeeze vs. Platypus Quickdraw for thru-hiking, see our section comparing the two filters below.
Best water filter for groups and Best Gravity Filter: Platypus GravityWorks 4L
Weight: 11.5 ounces
Type: 0.2-micron filter
Liters per Minute: 1.75
MSRP: $135
Removes microplastics? Not stated
Best for: Groups of 3+ people
What we liked: low effort, great for groups
What we didn’t like: price and weight
Winning our award for Best for Groups, the Platypus GravityWorks 4L involves the least amount of work among all the water filtration systems we tested. All you do is fill the “Dirty” bag, hang it higher than the “Clean” bag, and open up the line to send a liter per minute into the “Clean” bag below. It’s that simple. The system is heavy in the pack and on the wallet – over twice the weight and price of the Sawyer Squeeze – but we believe it is worth both the cost and bulk. And with a lifetime of 1,500 liters per filter, the entire system costs about $0.09 per liter.
Maintenance is simple. All you have to do is keep some water in the “Clean” bag after filtering and raise it higher than the dirty bag to send the water back through the filter. With a 0.2-micron filter, which means you’re safe from the major microscopic concerns in the US and Canada.
Our tester, Sirena Rana, likes that the Platypus GravityWorks can process large amounts of drinking water quickly (a necessity when finding water might be a once-per-day affair—or even less frequent). She also praised its ability to handle silty water and to maintain in the field easily. She uses the clean and dirty bags for additional water storage in the desert and as backups.
The GravityWorks is not a perfect system. A more significant argument against the GravityWorks is that the Sawyer Squeeze can also act as a gravity filter at less than half the cost, while also working as an on-the-go filter. Still, these complaints feel nitpicky for the speed and ease with which the Platypus GravityWorks provides a lot of potable water for a little effort.
Compare Prices of the Platypus GravityWorks 4L
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Best Water Purifier for Backpacking: MSR Guardian Purifier
Weight: 17.3 ounces
Type: 0.02-micron filter
Liters per Minute: 2.5
MSRP: $390
Removes microplastics? Yes
Best for: International travel
What we liked: high quality and durability, filters viruses, backflushes itself
What we didn’t like: price
If you’re headed backpacking in a country where viruses lurk in the groundwater (which calls for water purification), you’ll want to have the MSR Guardian with you. Where 0.2-micron filters like the Platypus GravityWorks are big enough for viruses to pass through, the MSR Guardian’s 0.02-micron, military-grade pump water filter catches everything. It also uses about ten percent of the water it filters to backflush itself, essentially eliminating the need to clean this filter by hand.
MSR drop-tested it from six feet onto concrete and freeze-tested it to make sure the filter doesn’t break in freezing weather. Even with hand pumping, it filters 2.5 liters per minute. But you pay for what you get: the MSR Guardian is among the heaviest of our reviewed filters at 17.3 ounces and is a staggering NINE times the price of systems like the Sawyer Squeeze. However, with a lifetime of 10,000 liters, the $0.04 price per liter is among the lowest of water filters reviewed.
It is fairly easy to use: toss the tubing into the water, set the filter on top of your bottle, and hand-pump clean water into your container. Our tester even recommends it for groups, despite the hand-pumping — it’s easy to spread the work out among group members. She also reported clogs in silty water—an issue easily resolved by pre-filtering the water (you can also gather it into a bottle or bucket and let it settle a bit before filtering off the top).
The MSR Guardian is the only hand pump system that made the cut for us. Having walked tens of thousands of miles, we think a pump water filter is laborious, heavy, prone to breaking, and generally wouldn't recommend them — but the durability and features the Guardian offers won us over. If international travel and water purification are in your cards, the MSR Guardian is the best purifier you can get.
Compare Prices of the MSR Guardian Water Purifier
Best Water Filter for Short Trips: Katadyn BeFree 1L
Weight: 2.3 ounces
Type: 0.1-micron filter
Liters per Minute: 2.0
MSRP: $45
Removes microplastics? Not stated
Best for: Hikes and trail runs, mountain runoff and streams, one person
What we liked: lightweight, quick filter
What we didn’t like: requires hacks for longer trips
The Katadyn BeFree is a filter that’s essentially the lid on a collapsible water bottle. One of the lightest filters we tested at 2.3 ounces, it filters a liter just about as fast as you can drink it. At 0.1 microns, it filters out everything but viruses, and at a lifetime of 1,000 liters, the price per liter is about $0.05. While we reviewed the 1-liter version, 0.6- and 3-liter versions also exist if you need more or less drinking water for your excursions.
Our tester on the Pacific Crest Trail found that initially, the water flow rate was considerably faster than the Sawyer Squeeze, but within two weeks, the flow rate was no better than the Sawyer. He also paired it with a Cnoc water container with BeFree threads, bypassing the water bag that comes with the filter (the soft bottle that comes with the filter doesn’t last long term). We also used the BeFree filter component with a homemade system that uses a stuff sack and medical tubing. This system isn’t commercially available, but it solved the capacity issues that make the Katadyn BeFree system our recommendation for short trips only.
Still, for shorter outings with lots of water, the Katadyn BeFree is a handy, lightweight filter with a strong flow rate.
The Katadyn Befree with bottle is the winner in our Best Water Bottles for Hiking guide for its easy-to-use fully inclusive filtering system.
For 2025, Katadyn announced a new Activated Charcoal (AC) version called the Katadyn BeFree AC. We are currently testing this product and look forward to reporting back soon.
View the Katadyn BeFree 1L Water Filter
Best water filter for trail running: MSR Trailshot
Weight: 5.2 ounces
Type: 0.2 micron hollow membrane filter
Liters per Minute: 1.0
MSRP: $63
Removes microplastics? Not stated
Best for: trail running, day hikes, shallow water or puddles where pumping is preferable to scooping, one person
What we liked: simple to use, versatility
What we didn’t like: maintenance, tannins will clog it
It feels so good to come across a burbling stream with a clear, strong flow, knowing that’s what you’ll be drinking shortly. It feels less good to come up to a stagnant puddle and know that’s your only water source for the next five miles. Enter the MSR TrailShot. It’s kind of like a water filter straw and squeeze filter hybrid. Just place the plastic intake tube in the source, work the miniaturized hand pump by squeezing your fingers, and you’re filtering comfortably from still water sources like puddles, lakes, and even cow troughs. If you’re looking for something for shorter trips or trail running that’s lightweight and easy to store in your running hydration vest, the MSR TrailShot might be for you.
The TrailShot takes about a minute to filter a liter of drinking water through the 0.2-micron filter. With a lifespan of 2,000 liters, it’s one of the cheapest filters over time at $0.03 per liter. And while it’s not the lightest filter in the review at 5.2 ounces, it has one of the smallest packed sizes.
MSR recommends cleaning the filter after every 8 liters. For most people, this means after every trail run or day hike, which isn’t great. We’ve found this recommendation about right — otherwise, the flow rate is greatly reduced, especially if the water is murky or has visible tannins in it. On the other hand, it’s relatively easy to clean — simply fill the bulb halfway with water, shake for 20 seconds, and then squeeze the dirty water back out the intake valve.
Overall, our tester liked the ease of use and adaptability. You can drink directly from the filter or pump it into a water bottle or hydration reservoir. But we don’t recommend it for long trips or large groups. Still, if you’re in the market for a portable water filter and don’t want to wrestle with hydration bladders when filtering out of small, shallow puddles, check out the MSR TrailShot.
COMPARE PRICES OF THE MSR TRAILSHOT
Best Heavy Metal Water Purifier: Grayl UltraPress Water Filter and Purifier Bottle
Weight: 12.5 ounces
Type: Electro adsorption and activated carbon
Liters per Minute: 3.0
MSRP: $90
What we liked: best-tasting water, removes everything, requires no maintenance
What we didn’t like: slow filter, heavy, high cost per liter
While less practical for trail backpacking, if you’re looking for a filter that removes everything, Grayl UltraPress Water Filter and Purifier Bottle is for you for any sort of international adventure travel.
While taller and skinnier than a Nalgene and relatively heavy at 12.5 ounces, this filter wins for subtlety, as it looks much like a coffee cup (in fact, it fits in most cup holders).
It functions much like a French press — pour contaminated water in, press the filter down slowly, and let the electro adsorption (read: bitty electrical charge) remove protozoan cysts, bacteria, viruses, and micro plastics.
A true water purification system, activated charcoal also absorbs particulates, chemicals, pesticides, herbicides, VOCs (volatile organic compounds), and some heavy metals. If you’re using this to treat tap water while traveling internationally, the carbon filter will help eliminate bad tastes without the need for drink mixes or electrolytes to mask odors.
But it only filters 16.9 ounces at a time, and depending on how you press. This is likely the slowest filter in the review (the manufacturer claims 3 liters per minute but our attempts are much slower). It’s also the most expensive when it comes to price per liter filtered; as each replaceable filter only goes for 150 liters, the cost per liter shakes out to $0.60 per liter. Still, that may be less than you'd spend hunting down bottled water and means the water in your hotel or hostel can be drinkable (plus, you're reducing single use plastic).
Our tester found that it’s difficult to tell when to change the filter. Grayl states that when press time has reached 25 seconds or after 3 years from the date of first use, you have to replace the filter. On the plus side, there is no maintenance or backflushing required!
Grayl also sells a 710 mL (28 ounce) titanium version that can also be used on a stove to heat water for your instant coffee, tea, or freeze-dried meals. We love it when one piece of gear has multiple functions!
View the Grayl Ultralight Purifier Bottle
Best UV Water Purifier: Katadyn Steripen Ultra UV Purifier
Weight: 4.9 ounces
Type: Ultraviolet light purifier
Liters per Minute: 1 liter in 90 seconds
MSRP: $130
Removes microplastics? No
Best for: hiking, backpacking, solo
What we liked: lightweight, price per liter, easy to use
What we didn’t like: ineffective in murky water, battery-dependent
It’s not exactly a filter per se, but we like the rechargeable Katadyn Steripen Ultra UV Water Purifier for its quick and easy use. It’s a purifier like both the MSR Guardian and Grayl Ultralight Purifier Bottle — so it removes viruses as well as protozoa and bacteria, but not chemicals or heavy metals. The advantage? The only effort you put in is turning it on, sticking it in your bottle, flipping the bottle upside down, and swirling it for 90 seconds. Sure, that’s longer than the other filters in this review, but at 4.9 ounces, including the charging cable, it’s the lightest purifier in our review. Unlike mechanical filters, it uses ultraviolet (UV) light to destroy 99.9% of microorganisms.
With a lifetime of 8,000 liters, or 50 liters per charge, the price is about $0.02 per liter — one of the cheapest filters in our review. The catch? It’s ineffective in murky water, so you’ll definitely need to pre-filter if you want to make sure you’re in the clear. It’s also dependent on its battery, so if that goes, so does your ability to purify your water.
Our tester carried a Steripen on her thru-hike of the Continental Divide Trail and has nothing but good things to say about it. It never broke or failed in cold temperatures. The battery life was true to the manufacturer’s claim. She used it in some seriously questionable water sources and didn’t get sick. However, cold temperatures will deplete the battery, so she slept with it at night to prolong the battery life.
Compare Prices of the Katadyn Steripen Ultra UV Water Purifier
Best Chemical Water Treatment: Aquamira Water Treatment Drops
Weight: 3.15 oz
Type: Chemical purifier
Time to treat: 20-35 minutes
MSRP: $15
Removes microplastics? No
Best for: hiking, backpacking, solo
What we liked: Ease of use, reliable
What we didn’t like: Time it takes to treat
Aquamira Water Treatment Drops are two bottles (Part A and Part B) that you mix before adding to the water. The active ingredient, chlorine dioxide, removes protozoa, bacteria, and viruses. It’s iodine-free, lightweight, inexpensive, and has a four-year shelf life after the date of manufacture.
Nearly every Treeline Review writer that is also a thru-hiker has used Aquamira on the Pacific Crest Trail, Continental Divide Trail, and beyond.
We’ve used Aquamira over thousands of miles on multiple thru hikes with no ill effects. In fact, chlorine dioxide is the same chemical used by many municipal water systems in the United States to treat public drinking water and is considered safe by the CDC.
One downside is that the drops take a while to do their job–five minutes for activation, then another 15-30 minutes for sterilization, depending on how turbid (murky) or cold the water is. But if you’re trying to make miles, you can add the Aquamira to your water and let it do its magic while you hike.
We also like to carry Aquamira as a backup treatment method or as a way to treat really bad water in conjunction with a filter.
Compare prices of the Aquamira Water Treatment Drops
Best Affordable Water Filter: Sawyer Mini
Weight: 2.0 ounces
Type: 0.1-micron filter
Liters per Minute: 0.625 L/minutes
MSRP: $25
Removes microplastics? Yes
Best for: emergencies
What we liked: price, ease of use
What we didn’t like: flow rate
We’ve used both the Sawyer Mini and Sawyer Squeeze over thousands of miles and diverse terrain, from desert to alpine (the Mini is just like the Squeeze, but smaller and slower). Overall, we’ve found that the weight penalty with the Squeeze is worth the better flow rate. Especially for longer trips, the slower flow rate was frustrating.
However, if you’re not concerned with flow rate and want to save both money and weight, the Sawyer Mini can’t be beat.
COMPARE PRICES OF THE SAWYER MINI
Other Water Filters and Purifiers We Tested
Lifestraw Peak Water Filter Straw
Weight: 2.3 oz
Type: Straw filter
Liters per Minute: 3
MSRP: $25
Removes microplastics? Not stated
Best for: emergencies
The LifeStraw Peak Water Filter Straw is a lightweight, easy-to-use filtration straw you can place directly in a water source. It filters out bacteria and protozoa, but does not filter out viruses or heavy metals. Additionally, it doesn’t allow for carrying water on you – just for direct use of present water sources. We wouldn’t necessarily recommend this for backcountry use unless you’re also carrying a water source, but it can be a handy, inexpensive tool for traveling or in your emergency preparedness kit.
Compare prices of the Lifestraw Peak Water Filter Straw
Weight: 1.7 oz
Type: Squeeze
Liters per Minute: 3 L
MSRP: $29
Removes microplastics? Not stated
Best for: emergencies
The Lifestraw Peak Series Solo Water Filter is an affordable and stylish water filter available in many color options. We think it is best for emergency situations or hikes where you don't plan to filter water but want to have something just in case. You can screw it onto a water bottle and it lasts for up to 2,000 liters (528 gallons). We like that unlike other budget filters, it has a top and bottom cap for leakproof storage. We also like that Lifestraw is a B-corp and for every LifeStraw product purchased, a child in need receives safe water.
In the field, the Lifestraw was slower than the 3L per minute claimed, even after we'd taken the proper measures to prime the filter before leaving home.
View the Lifestraw Peak Series Solo Water Filter
Weight: 2.9 oz
Type: Hollow fiber, squeeze
Liters per minute: 3
MSRP: $45
Type: 0.1 micron absolute filter
Removes microplastics? Yes
Best for: people who want a Sawyer filter and already have a CNOC bladder
Nearly identical to the Sawyer Squeeze with CNOC Bladder system that we recommend, this version of the Sawyer Squeeze comes with the traditional Sawyer dirty water bottles. The filter is the same. The CNOC bladders are more durable and easier to squeeze that the bags that come with this system. It's still a good option to save a few bucks if you already own CNOC bladders or know you won't use CNOC bladders.
Sawyer Squeeze Water Filter System
Weight: 5.7 oz (filter only)
Type: Hollow fiber, squeeze
Liters per minute: 3
MSRP: $75
Removes microplastics? Not stated
Best for: Hikes and shorter backpacking trips, mountain runoff and streams, groups
This is the same Platypis QuickDraw we love but with a hose and attachment and bag system that turns it into a gravity filter. Unfortunately, the 2 L Platypus bag that it comes with doesn't have a handle. That means that you have to hold it upright in order to gravity feed water through the filter. While we didn't test the 3L system, we've read reports that the handle had a high rate of following off. So as much as we love the Platypus QuickDraw, we think you may be better off sticking with the original version.
Platypus QuickDraw Gravity 2L
Weight: 18.7 oz
Type: 0.2-micron gravity
Liters per Minute: 0.5
MSRP: $300
Removes microplastics? Yes
Best for: international travel, groups
The MSR Guardian Gravity Purifier is a lightweight personal gravity filtration system that filters out bacteria, protozoa, viruses, and chemicals. At $300, it’s more expensive than other options, but between the quality of the filtration and the 3,000+ liter cartridge life, it is a worthwhile investment. Similar to the MSR Guardian Purifier, this is a military-grade filter that weighs more than other systems we tested, but works very well. The difference between the two is the Purifier is a pump filter, whereas the Gravity is a gravity filter.
MSR Guardian Gravity Purifier
Weight: 15.9 oz
Type: Press action
Liters per Minute: 5
MSRP: $100
Removes microplastics? Yes
Best for: international travel, urban areas
We appreciate the Grayl GeoPress for its ease of use–with a simple pressing motion, you can have 24 fl. oz. of water free from viruses, bacteria, protozoa, chemicals, and heavy metals.
The bottle is well-designed and is a classic filter-bottle best used for travel. At 15.9 oz. for just 24 fl. oz. of water, you certainly wouldn’t want to rely on this for hiking or backpacking.
However, we prefer the similar Grayl UltraPress water filter because it is lighter, more compact, and less expensive. The UltraPress can fit better into backpack pockets as well as other places you may travel, such as cup holders.
Grayl GeoPress Water Filter and Purifier Bottle
Weight: 11 oz
Type: Pump filter
Liters per Minute: 1
MSRP: $90
Removes microplastics? Not stated
Best for: hiking, backpacking, solo
The Katadyn Hiker Microfilter filter takes 48 strokes (about one minute) to remove protozoa and bacteria from one liter of water. Designed for backpacking, it weighs 11 oz. and costs about $0.12/liter. While it’s not the lightest or most cost-efficient option, but it’s durable. We’ve known hikers who have used their filters for over 10 years. So if the specs don’t bother you, this is a quality, long-lasting option.
Katadyn Hiker Microfilter
Weight: 0.9 oz
Type: Chemical purifier
Liters per Minute: 1 liter/ 4 hrs
MSRP: $16
Removes microplastics? No
Best for: emergencies
These tablets use chlorine dioxide to remove protozoa, bacteria, and viruses from water. The upside is they are effective, ultralight, and inexpensive. However, they take a whopping four hours to sterilize the water and are the most expensive purifier we tested ($0.53/liter). In our opinion, the Katadyn Micropur MP1 tablets make a great backup option to have on hand for emergencies. We carry them in our emergency kits in case a filter fails or is lost, but wouldn’t recommend them as the primary form of filtration.
Katadyn Micropur MP1 Tablets
Weight: 2.5 oz
Type: Inline filter
Liters per Minute: 1.5
MSRP: $50
Removes microplastics? Not stated
Best for: hiking, trail running, backpacking
The MSR Thru-Link attaches to water reservoirs for on-the-go filtration. It filters protozoa and bacteria and can be used as a gravity filter at camp. This inline filter system is ultralight and incredibly cost-efficient ($0.03/liter). Due to the design, it is ideal for one person rather than groups.
MSR Thru-link Inline Water Filter
Weight: 2.6
Type: Bottle lid attachment
Liters per minute: 1 L/min
MSRP: $45
Removes microplastics? Not stated
Best for: day hiking
The DayCap is compatible with Nalgene Wide Mouth, Hydro Flask Wide Mouth, Yeti Yonder™, and CamelBak Wide Mouth bottles. We tested the DayCap with Hydro Flask and my Nalgene bottles for our Best Water Bottles for Hiking guide, and it worked well and was leak-free with both kinds of bottles. The hollow fiber filtration is the same used in other Platypus products, and is individually tested to ensure it meets all EPA & NSF guidelines for the removal of 99.9999% of bacteria and 99.9% of protozoa.
Unlike some filters that require heavy suction and squeezing, it only takes a light pull to get water through the spout and feels almost as easy as normal drinking. We never found the flow to slow down during testing, but Platypus recommends shaking the bottle with the filter still on to clean it and restore the flow rate. The cap and loop feels just as durable as the original lid and carry loops on Nalgene and Hydro Flask bottles, and we easily hung the bottle on a tree branch without any fear of it snapping or breaking.
However, this filter is best suited for day hikes and is not ideal for backpacking, as it’s difficult to move filtered water from the bottle to another receptacle, like a cookpot, for making food.
Platypus DayCap In-Bottle Filter
Filtering water doesn’t have to be a chore! Here, Treeline Review writer Sam Schild is filtering using the new Sawyer Microsqueeze with the CNOC premium bag. Photo courtesy Sam Schild.
Backpacking Water Purifier vs Filter: What’s the Difference?
The difference between backpacking filters and purifiers is the level of protection. Filters remove protozoan cysts and waterborne bacteria. Purifiers remove protozoan cysts, bacteria, AND viruses. It’s generally considered safe to only use a filter in North America where viruses are uncommon in the backcountry. However, with the rise of Norovirus outbreaks on the Appalachian Trail, some hikers are choosing to carry a purifier instead.
For international travel, a purifier is almost always recommended.
How to Choose the Best Backpacking Water Filter for You
Turns out, there is no one-size-fits-all when it comes to backpacking water filters. To find the best water filter for you, ask yourself a few questions:
Are you backpacking, trail running, or traveling internationally?
The Platypus Quickdraw water filter screws onto a Smartwater bottle (threading on the bottom) and screws into the Platypus Dirty bag that it comes with (threading on outside). It comes with a retractable lid. This makes it easier to put away your filter at night without drips. Photo by Sara Kruglinski.
Are you headed out for a trail run, going backpacking for a month, or traveling abroad for a year? What you’re doing — and who you’re doing it with — will go a long way to helping you decide on the perfect water filter for you. For folks filtering their own water, the Sawyer Squeeze is the most adaptable filter, able to go along on a day hike or a long-distance backpacking trip with equal ease. For fast travel or trail running, you might want something quick and light like the MSR Trailshot. For shorter overnight trips, we recommend going with the Katadyn BeFree. If you’re settling into international life, something less conspicuous with more hardcore water filtration like the Grayl UltraPress Purifier Bottle might be best. For groups, a larger-capacity water filtration system like the Platypus GravityWorks will make life easier. Finally, if you’d like something that purifies it all — waterborne bacteria, cysts, and viruses, an ultraviolet purifier like the Katadyn Steripen Ultra is your best bet.
Will you be in North America?
Traveling in the US or Canada, or going farther afield? In most of North America, we’ve taken care of our sewage problems, you don’t have to worry about viruses in the water — but in other countries, that may be a different story. A filter like the Sawyer Squeeze, which has pores a tiny 0.1 microns across, is appropriate for places where there’s little risk of sewage contamination. If you’re traveling in countries where the water’s known to make visitors sick, you’ll need a usually-more-expensive solution in the form of a purifier, like the MSR Guardian, Grayl UltraPress Purifier Bottle or SteriPen Ultra, to make sure you get all the bad stuff out.
What’s your water source?
Streams, lakes, puddles, rivers, even sinks — we’ve filtered from all sorts of sources, and some filters are better at some sources than others. For example, the MSR Guardian and the Grayl UltraPress Purifier Bottle will take ickies like norovirus out of your water — but the Guardian is a bit of a bear to use in a sink, and you have to be much more careful about cross-contamination using the Grayl by the side of a stream.
Liz Thomas using the Sawyer Mini in the Sierra Nevada mountain range. The Mini is best suited for shorter trips in areas with particular pristine water, like the Sierra. Photo by Whitney LaRuffa
What’s your budget?
That bottom line is important, too. Over half of the water filters in our review were around the $50 mark at the time of publishing; the others ranged from the low $100s to more than $250 for extra-super-clean and safe water. You’ve got to choose the best filter for your adventure in your budget, and we’ve tried to link you to the best deals.
What about a straw filter?
In our experience, straw filters, such as the LifeStraw Personal Water Filter, are not suited for backpacking and hiking. They’re too inconvenient and the flow rate is too slow. They’re best left for other situations.
What are the potential water contaminants in the areas you’ll be using the filter or purifier?
Most filters, like the Platypus QuickDraw, the Katadyn BeFree, and the Sawyer Squeeze, filter out protozoa and bacteria. This is handy for basically anywhere in the U.S. and elsewhere, depending on your travel. However, some places you travel may have a higher risk of viruses in the water. In such cases, you’d want a purifier that removes viruses, like the MSR Guardian Purifier. If heavy metals are a risk where you’re traveling, the Grayl UltraPress Purifier is a good option.
How portable does the filter/purifier need to be?
If your plans include a long backpacking trip, a lightweight and portable option, like the Platypus QuickDraw or Sawyer Squeeze, is ideal. If you’re traveling somewhere and have the capacity for a larger filter/purifier, then portability is less important. The MSR Guardian Purifier, for example, wouldn’t be ideal for backpacking, but could be easily stored in your place of lodging on a trip.
What is the filter’s flow rate? Does it meet my hydration needs and demands of the activity?
This is a great consideration that requires knowing yourself and your needs. Do you have the time and patience for the four hour wait of the Katadyn Micropur M1 tablets? Would your activity be better suited by the 20-second wait of the Platypus QuickDraw? The Grayl Geopress filters a liter of water in about 12 seconds, but is a bottle ideal for your activity? You’ll want to consider here both the flow rate/purification time as well as the shape and size of the system.
Treeline Review tester Graham Hodge using the Quickdraw filter in notoriously silty water of the Pacific Northwest. Photo by Graham Hodge.
How user-friendly is the filter/purifier? Is it easy to set up, operate, and clean in the field?
When you’re in a situation in which you need to filter water, it’s not the best time for a cumbersome, confusing, or difficult process. This is especially vital if, Heaven forbid, you’re dehydrated and delirious (though we hope your hydration system and habits have prevented this!). Be sure you feel comfortable operating and cleaning the filter/purification system. There’s no shame in watching tutorials if you’re unsure, and it’s always a good idea to practice before using anything in the backcountry or abroad.
Are there any safety certification or third-party testing results available for the filter/purifier?
It’s a good sign when your filter/purification system has been third-party tested and certified. For example, when we were debating the merits of the Platypus QuickDraw versus the Sawyer Squeeze, we noticed the QuickDraw filter size is 0.2 microns, while the Squeeze filter size is 0.1 microns. While that initially makes the Squeeze feel like the safer option, ultimately both products have been tested and meet both the EPA (Environmental Protection Agency) and NSF (National Sanitation Foundation) standards. Those safety certifications make us feel confident about both products.
What to look for in a water filter
Treeline Review writer Felicia Hermosillo using the BeFree filter on a thru-hike of the Uinta Highline Trail in Utah.
What’s the best backpacking water filter? That’s a pretty personal question, and a pretty personal choice. While we’ve sorted out the ones we think are best for any application, below are points to ponder when you’re making your personal choice.
Weight
Sure, you need clean water — but there’s a balance between weight and convenience for everyone. Our systems range from a barely-there 2.3 ounces to a hardcore 22 ounces — but how much a system weighs often has to do with whether or not it filters out viruses. Viruses are usually found in sewage-tainted water, so they’re not a primary concern in places like the US or Canada. But you might need to sacrifice weight if you’re traveling to a place where the drinking water is known to make people sick (even if it’s considered to be potable water). Pay close attention to your needs while you’re looking at weight, to make sure you have the right tool for your adventure.
The Platypus GravityWorks system uses a “dirty bag” and a “clean bag system.” Photo by Sirena Dufault
Ease of Use
Trust us — you do not want to use one pressure or hand pump system to filter water for eight people. Likewise, you might not want to carry the weight of a gravity filter system if it’s just you by your lonesome. When choosing your backpacking water filter, think about what’s going to be easiest for you while you’re out on your adventure. Because if you get into camp and decide you’re too tired to hand pump your water through your filter (which we’ve definitely never done, not even once, why are you asking?), you’re going to have a thirsty time.
The MSR Guardian uses 10% of the water to backflush itself.
Wait Time
Nothing’s instantaneous when you’re outside doing things for yourself — and water filtration isn’t any different. Still, different water filters have different wait times — the length of time you have to wait to turn that dirty water into clean water. All of the backpacking water filters in our review give you a liter of filtered water in 90 seconds or less, but when you’re thirsty and just gotta have that sweet sweet H2O, every second might count. So ask yourself: how patient are you, really?
The Sawyer Squeeze can easily be screwed on to the top of a plastic water bottle to filter water as you drink. Here, Treeline Review co-founder Naomi Hudetz is filtering water on the Great Divide Trail in the Canadian Rockies. Photo by Liz Thomas
Filter Lifetime
At $50 or more per water filter, you’re not going to want to buy a new one every time you get a new adventuring idea. As such, you’re going to want to check on how long each filter lasts — and, if you’re choosy, the price of the filter per liter of clean water it produces over its lifetime. That price per liter ranges from $0.60 per liter all the way to less than $0.01 per liter, so you can find your own personal sweet spot. You’ll also want to think about that filter’s end-of-days. Some models have replaceable parts or filters, so you don’t have to replace the system entirely — and if that’s what you’re looking for, choose accordingly.
What it Filters
Traveling in the US or Canada, things are pretty simple — all you need is a filter, and all of our reviewed models fit the bill. For example, to filter out giardia and cryptosporidium, illness-causing microbes that can be found in some US water sources, you need a filter with an absolute rating of 1 micron; all the filters we reviewed have openings that are 0.2 microns or smaller, unless they purify through UV light. If you’re traveling farther afield, though, you’ll want a water purifier, which is a filter that stops viruses, too. Viruses are smaller, so that requires a little more oomph, whether that’s in the form of a smaller filter size, electro adsorption (read: bitty electrical charge in water kills bad stuff) tech, or UV light.
The Platypus GravityWorks system allows you to put very silty water into your “dirty bag.” Field maintenance is also easy. Simply flip your filter system so that clean water runs from the “Clean Bag” into the “Dirty Bag.” As it falls through the filter, things that can create clogs will dislodge from the filter into the dirty bag. Photo by Sirena Rana.
Capacity
Be sure the filter/purification system holds an appropriate amount of water for your needs. If you’ll be in the backcountry where water is less available, you’ll want a larger capacity. If you’re traveling internationally but will have easy access to water, the water capacity is less important and you may want a smaller vessel for ease of carrying.
Filtration and Purification Methods
1. Mechanical Filtration
This method describes water passing through a filter or cartridge to clean water. This method is best for removing protozoa and bacteria from water.
2. Activated Carbon Filtration
In this process, carbon soaks up organical chemicals (particularly the ones that smell bad, like chlorine or sulfur), heavy metals, and other contaminants.
3. Chemical Purification
This is when you use chemicals–typically in the form of tablets or drops–to purify water from bacteria, protozoa, and viruses. These are handy and easy, but don’t have the lifespan or excellent price-per-liter like other options.
4. UV Light Purification
UV light purifiers, like the Katadyn Steripen Ultra UV Water Purifier, kill microorganisms in water. This is great in that it destroys bacteria and viruses, but it is limited to microorganisms. It cannot purify heavy metals or man-made substances.
Replacement Filters and Availability
A Treeline Review tester running water through the Platypus QuickDraw filter in the Sierra. The QuickDraw recommends changing out filters every 1,000 L.
Keep in mind, filter cartridges and purification elements will need to be replaced after the advertised number of uses. You’ll want to make sure those replacement parts are available.
Compatibility With Different Water Sources
Consider the sources of water you’ll likely be drawing from–ponds, rivers, faucets, snowmelt, lakes, etc.–and which type of device is going to work best for that source. For example, if you’re drawing from bodies of water in the backcountry, a LifeStraw isn’t going to be your best option. However, it would work if you’re traveling and have frequent access to water.
Using the Sawyer Mini filter to purify water from a cow trough on the Wasatch Traverse in Utah. If we were to do this trip again, we would' have brought the Sawyer Squeeze. Photo courtesy Liz Thomas.
Taste and Odor
Keep in mind that some filters/purifiers do not fully remove unpleasant tastes and odors from the water. Not only will you need to decide if that’s something you can endure, but you might also consider whether or not you can and are willing to pack electrolyte tablets or flavor droplets to mask the taste.
Environmental Impact
Consider the environmental impact of the filter/purifier–are the filter cartridges recyclable? Will you need to replace pieces frequently?
Cold Weather Performance
If you plan to backpack in colder climates, check if the filter/purifier is designed to function effectively in freezing temperatures.
Platypus Quickdraw vs. Sawyer Squeeze
Treeline Review co-founder Liz Thomas filtering with the Platypus QuickDraw filter in the Eastern Sierra.
There's a lot of debate about the Sawyer Squeeze vs. the Platypus Quickdraw for thru-hikes. After thousands of miles over three years as tested by half a dozen Treeline Review testers on thru-hikes and bikepacking trips in different climates (desert, mountain, areas with glacial streams) across the US, here is our take:
Over longer periods of time, like a 1000+ mile thru-hike, the Quickdraw loses its flow rate whereas the Sawyer does a better job restoring it with backflushing. So while the Quickdraw starts off faster, the Squeeze stays faster over a longer period of time.
Sawyer advertises that they have thick fiber walls that are ~75% stronger than fibers of other typical hollow fiber membranes. We can attest to the Sawyer's ability to handle aggressive and continual backwashing. We've never achieved the 98% of the original flow rate that Sawyer claims after a backwash, but we've backwashed the heck out of these filters.
Sawyer filters are good for a million gallons. The Quickdraw requires a replacement filter cartridge after 250 gallons.
Squeeze or QuickDraw depends on your trip length:
Ultimately, we think for shorter thru-hikes in areas with mountain run off (like the John Muir Trail and Colorado Trail), many hikers will appreciate the faster flow rate of a Platypus Quickdraw.
For longer thru-hikes in areas with less reliable water like the Arizona Trail, Continental Divide Trail, or Pacific Crest Trail, we recommend the Sawyer Squeeze, which will backflush easier and maintain flow rate over longer periods of time.
Treeline Review writers' takes on Quickdraw vs. Squeeze:
Treeline Review writer Graham Hodge chose the Quickdraw as his favorite gear item of the year when it came out and it’s featured in his Bikepacking the Lower Deschutes Trail guide. He tells us, “I have used this filter for about 200 miles of Central Cascades Trails. As much as I avoid it, that area is notorious for silty water. I have certainly had to filter less-than-ideal water sources. I am not claiming that this filter is clog-free, but I have not needed to backflush it once since purchasing, and the flow rate is still impeccable.”
Treeline Review writer Sara Kruglinski writes. “It has a streamlined design that is well thought out on the details. For example, the cap for the dirty bag nests in with the bottom cap of the filter, so they are harder to lose.”
Treeline Review writer Sam Schild writes, “The Quickdraw held up for the entire Grand Enchantment Trail and seems to take longer to clog than the Sawyer Squeeze. I used the Sawyer Squeeze for the entire Pacific Crest Trail and Continental Divide Trail (replaced multiple times). The Squeeze is easier to clean thoroughly, since you can use the included syringe. But, the Quickdraw is easier to clean in the field since you only need a SmartWater bottle to backflush it (or just swishing it in some water works pretty well). The Quickdraw also has a better cap than the Squeeze. Overall, I think they’re very similar and would confidently rely on either filter. The Quickdraw is perhaps slightly more durable.”
Treeline Review founder Naomi Hudetz writes, “I usually carry the Sawyer Squeeze rather than the Platypus QuickDraw because the Squeeze can also be used as a gravity system using a Sawyer coupler. I frequently hike in desert areas with long water carries, and it’s easier to let gravity do the work. If there are no trees around, I make a tripod with my trekking poles!”
Using the Sawyer Squeeze as a gravity filter on the Arizona Trail. Photo by Mike Unger.
Water Filtering Tips & Tricks
1. Check your filter before you leave home
Always check to make sure your backpacking water filter is working before you leave. Whether it’s a faulty UV lamp or a tear in a filter, manufacturing defects happen, and it’s best to know about them before you head out into the wilds. Many filters have a way to check on whether or not they’re working correctly, and checking them before you leave home will help you stay happy and healthy on your adventures.
2. Carry a backup method
Consider carrying a backup filtration method. We don’t talk about backups in our review, but they’re a good idea. If for some reason your filter becomes inoperable, it’s best not to have to sit around your stove and boil water for the 1-3 minutes the EPA says it takes to purify it every time you want a drink. Most folks carry some form of backup chemical purifier, such as iodine purification tablets or chlorine dioxide droplets.
3. Pre-filter your water
Looks gross? Consider pre-filtering. That water source that has a lot of dirt/leaves/bugs in it? All that extra junk is probably going to clog your filter, making it less efficient at best, or less effective at worse. If you carry something like a bandana, coffee filter, or Dollar Store pantyhose as a pre-filter, and pull all your water through the pre-filter before you filter it, you’ll keep your filter cleaner and keep that crap out of your drinking water to boot.
4. Add flavoring or electrolytes
Filtered water still has a gross taste? Consider adding some sort of flavoring. Plenty of outdoors people carry Gatorade powder for electrolytes, but other water-flavoring goodies, like Mio or fruity teas, can take the edge out of a particularly gross-tasting batch of water. If it’s your bottle or filter that tastes gross — usually like plastic — run some tap water with either lemon or lime juice through them before heading out. That should diminish that distasteful flavor. We use this same trick in our articles on Tips to Stay Hydrated while Trail Running.
The Katadyn BeFree water filter used with a Cnoc water container. Photo courtesy Liz Thomas
5. Avoid freezing and dropping your filter
Drops and freezing temperatures are not your friends. Each of these water filters is a delicate piece of equipment, and care needs to be taken to make sure they continue to work. Most of these filters have a hard time surviving falls, and water expanding into ice at freezing temperatures can also break them. The worst part? Without taking extra time to test them after an incident, you may not be able to tell that it’s broken. And those tests cost more than most filters.
Take special care to keep your filters secure, and if you know you’re camping at temps below freezing, consider sleeping with your water filter in your sleeping bag (double bagging it in a zip bag will keep you dry). Better safe than sorry. You can learn more in our winter camping gear checklist.
6. Collecting from still water
Collecting from still water with a collapsible bag? Patience is key. If you’re using the plastic collection bags that come with the Sawyer Squeeze, or hydration bladders like the Platypus or CNOC, you’ll need a technique to collect from lakes and other still water sources.
The Grayl Ultralight Compact Purifier Bottle works by pressing down slowly.
Wrap your hand around the opening, and gently blow through your hand into the bag to inflate it, allowing room for the water to enter while keeping contaminants away from your mouth. Then, skim your bag across the surface of the water until it gets enough weight in it to sink, which should let you collect more easily. If you know you’re going to be in an area where you’ll have to collect from shallow puddles, fashion a scoop by cutting the bottom third off a Sawyer bag or even a Gatorade bottle. Then, just scoop the water into your dirty container for filtering.
Another option is to use a Ziplock bag to scoop and transfer the water to your main container.
7. Use a purifier for international travel
Traveling internationally? Get a purifier. We know, we know, we’ve mentioned it a bunch, and purifiers are more expensive — but if you use your run-of-the-mill backpacking water filter in countries where the sewage systems aren’t the best, you’ll still potentially be exposing yourself to viruses. Numerous waterborne viruses cause the stomach flu, which can knock you out of commission for days at a time — so drop that extra cash and make sure you’re covered. Travel enough and you'll recoup your money by avoiding the expense of bottled water (and save the environment too!).
The Sawyer Squeeze used “inline” with a hydration bladder. How this system works: Cut the hydration hose tube in two. Insert the filter to connect the two pieces. Put dirty water into the bladder. When you suck on the tube, dirty water travels through the tube, into the filter, and comes clean out the bite valve. In camp, you can pop off the bite valve and turn the system into a gravity filter. Photo by Liz Thomas.
8. Label your water containers
Beware cross-contamination! Make sure you remember which bottles or bags are dirty and which are clean. Most systems have built-in reminders, but being extra-cautious never hurts. If you dip the filtered water bottle into a water source, make sure you rinse it with clean water before drinking. You wouldn’t want to filter and then have leftover nasties still waiting for you on your bottle’s lip.
9. Practice leave no trace
Want to worry less about clean or dirty water sources? Practice Leave No Trace. Many of the Seven Principles of Leave No Trace have to do with protecting water sources. One of the biggest sources of contamination? Fecal material. (Gross.) Make sure you’re doing your business at least 200 feet from water (and camps and trails, for that matter), and do your washing away from water for good measure, too.
Water Filter and Purifier Care and Maintenance
Follow manufacturer’s instructions
Even if you feel confident about how to use the filter, we highly recommend reading the manufacturer’s instructions. Not only will this ensure you’re using the product correctly, it will also give you maintenance and cleaning guidelines so your filter/purifier will run efficiently and last longer.
Prepare your filter for storage
Clean it before you store it. Most filters have a recommended method of cleaning. Usually, it involves running a watered-down bleach solution through the filter and drying it thoroughly before storing it. The last thing you want is to get ready for your next trip and find that mold’s grown in your filter (which has definitely never happened to us, not even once, so many questions, why are you asking). Take care of your equipment, and it can better take care of you.
Filter replacement
Replacing the filter cartridges (or purifier parts) on a consistent and regular basis is necessary for keeping the product effective. There’s no use in a water filter/purifier that no longer fully filters/purifies the water!
Backflushing
Some products, like the Platypus QuickDraw and Sawyer Squeeze, require backflushing to keep the filter clean and prevent the flow rate from slowing down. Again, be sure to read the manufacturer’s instructions for how to, and how often to, backflush.
Tester Mike Unger backflushing the Sawyer Squeeze in the field on the Mogollon Rim Trail. Notice the stream of brown, dirty water coming out of the bottom of the filter. Photo courtesy Naomi Hudetz
Cleaning
The filter isn’t the only thing that needs cleaned–be sure to keep all removable and usable parts clean. We recommend mild soap and warm water if possible, and reading the manufacturer’s instructions for any special cleaning tips.
Proper storage
Store your filter/purifier somewhere dry when not in use. This will help prevent mold or bacterial growth from happening when the product is not in use. Again, the manufacturer’s instructions should have storage guidelines too you should follow.
Pre-filtering
Pre-filtering involves manually filtering water before it even goes through the filtration system. This is a common practice in places with particularly mucky water in order to not clog the filter, and typically involves running the water through a cloth on its way into the bag or device. Not only does this help ensure cleaner water, it prevents clogging up the filter and keeps the device functioning for longer.
Winter care
If you plan to use your filter/purifier in freezing conditions, you’ll need to protect it from the elements. If ice forms in the device, it’s more likely to cause damage and not function properly. The Platypus QuickDraw, for example, has end caps on both sides so you can sleep with it in your sleeping bag to keep it warm without worrying about leakage. The manufacturer’s instructions may also include winter care instructions.
Inspections
Keep an eye on your filter/purifier and make a habit of inspecting it for damage, especially before trips. In particular, you’ll want to look for cracks, leaks, or pieces that don’t fit how they should. If damage is discovered, we recommend checking the warranty and calling the manufacturer for support.
Replacement parts
Sometimes, general upkeep and maintenance of the filter/purifier involves replacing parts. You may at some point need new filter cartridges, seals, or other pieces. You’ll want to keep track of filter usage so you’ll know when it’s time to replace the cartridge.
FAQ
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How often a filter cartridge or purifier element needs replaced depends on the product, and can be referenced in the manufacturer’s instructions. Most of the filters/purifiers we tested last anywhere from 150-10,000+ liters. That’s a large range, so definitely check the specs of your product.
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The answer to this mostly depends on the filter/purification system you’re using. A LifeStraw, for example, can be used directly in a source. On the other hand, many filters/purifiers need time to fully filter or purify the water, in which case you would want to collect the water. Tablets especially need a container in which to purify the correct amount of water the tablet is able to purify.
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The only surefire way to know if the filter/purifier is working is to test a sample of the water. This is not always a convenient or possible thing to do, especially if you’re in the backcountry. Some systems, like the Platypus QuickDraw, have an integrity test feature you can use to ensure the filter is working.
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Absolutely! You can use a water filter or purifier any time. In fact, it’s always a good idea to at least carry purification tablets or drops in case of emergency.
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As great as these filters and purifiers are, none of them come with a 100% guarantee for avoiding every contaminant. There is always the risk that the water you drink is unclean, regardless of the system used to clean it. Furthermore, purification tablets and drops are chemicals that, when used incorrectly or in excess, can cause irritation, illness, and abdominal pain. Any product has its own risks, so it’s always a great idea to read the manufacturer’s instructions and prepare for emergency scenarios.
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If you encounter irreparable issues with your water filter/purifier in the backcountry, the best thing to do is keep calm and come prepared with purification tablets or droplets, like the Aquamira Water Treatment Drops or the Katadyn Micropur M1 tablets. These are lightweight and great for emergency situations. If you’re able, boil water–that will kill most bacteria and protozoa (pre-filter through a cloth if the water is particularly cloudy). Do what you can until you can reach access to help and clean water.
How We Tested
We've been testing water filters and purifiers for six years and have tested more than two dozen types of water filters and purifiers.
We've aimed to test in all types of climates and ecosystems with hikers, backpackers, campers, and bikepackers of all levels of experience.
More than a dozen Treeline Review testers have taken water filters on thousands of miles of backpacking and bikepacking on destinations around the world to find the best water filters and purifiers for most situations.
We've tested in deserts, glacial silty water, high alpine lakes, and more cow stock ponds that we can count. We've tested filters side-by-side. We tested in temperatures well below freezing and temperatures up to 110F degrees.
Our tests of water filters include on day hikes with new hikers and on thru-hikes with seasoned backpackers.
Our testers of purifiers are also informed by personal experiences filters in hostels in Southeast Asia and sub-Saharan Africa.
About the Author / Why You Should Trust Us
I personally have hiked over 3500 miles, including thru-hikes of the Pacific Crest Trail and Colorado Trail and a LASH (long-*ahem* section hike) of the Grand Enchantment Trail. Between those hikes and a stint as a Traveling Trainer for the Leave No Trace Center for Outdoor Ethics, I've slept outside for nearly a year of my life.
Whether it's living on the road or living out of a backpack, traveling and just being in the outdoors is second nature to me. I’m an American Hiking Society Next Generation Trail Leader and a Vice-President of the board at the American Long Distance Hiking Association-West, which awards the Triple Crown of Hiking. I run the popular blog Brown Girl on the National Scenic Trail, a space for intersectional writing to encourage folks of all colors and all walks of life to experience our wild spaces and preserve them for the future. You can see all my Treeline Review articles on my author page.
