The Best Backpacking Water Filters of 2020
Best Overall for Group Use
The Platypus GravityWorks is an awesome backpacking water filter and maintains its podium for its fast and simple design. This gravity system features two super durable bags marked as "clean" and "dirty" to keep microbes out of your water. The transparent "clean" bag ensures that water is, in fact, clean, and can be hung to double as a solar shower or hand washing station. This ultra-versatile system is suited for all sizes of groups, from the solo hiker to a large basecamp.
Unfortunately, this system does not treat viruses and the bags can be hard to close in cold weather. Also, the hanging attachments look a little less durable than other options, with some online users reporting that they can rip out (though we didn't see any issues of the like). If you decide to travel internationally, you can swap out the filter for an in-line option that does treat viruses like the Aquamira Frontier Max or use chemical treatment in conjunction with it. In all, this gravity filter is hands-down our top recommendation for groups for filtering a large amount of water quickly and without the least hassle.
Read Review: Platypus GravityWorks
Best Overall for Personal Use
The Sawyer Squeeze is one of the most time-tested on-the-go filtration systems. This lightweight filter is perfect for personal use, providing great functionality on multi-day excursions and daily adventures into the backcountry. Of the multiple Sawyer Squeeze systems, this one offers the fastest flow rate, filtering one liter of water in just 40 seconds. We love how packable it is and the great level of longevity the filtration unit offers. It can be used as a squeeze-filtration system, an in-line filter with your hydration bladder, on top of a water bottle, or even as a straw to drink straight from the source. Versatility. And for the price, it's a screamin' deal for individual use in the backcountry.
While this is one of our favorites, our biggest caveat lies with the included squeeze bags. After filtering several liters, each of the squeeze bags that we tested failed at the seam. Luckily the filtration unit is compatible with many other products and fits a plastic water bottle, too. While these alternatives proved to be our preference, we'd say that Sawyer should thus work on making some stronger bags. In addition, because there are many parts, it's important to keep them together in the mesh bag and to avoid use in water with lots of sediment. Still, it's our favorite system for personal use in a crowded market.
Read Review: Sawyer Squeeze
Best Value Gravity Filter
Katadyn Gravity Camp 6L
We love the Katadyn GravityWorks for its super-easy-to-set-up design and fast flow rate. It treats vast quantities of water in minutes, making it an excellent option for a large group or solo us. The filling is easy as the water bag has a large opening and can easily be squished down. This system does need to be suspended from a high location and it'll do the rest while you do chores around camp. It's compatible with most hydration bladder systems and can double as a handwash station or shower.
Unlike other gravity filters in this review, it does not come with an additional storage bag for clean water. Because of the placement of the filter in the bag, it doesn't work well if there are no branches to hang it from. It clogged quickly when filtering water from the Colorado River after a heavy rainstorm. However, we were able to successfully unclog the filter and continue obtaining potable water. We found this simple gravity filter to provide a ton of value for anyone looking for large filtration capabilities without spending a large amount of money.
Read Review: Katadyn Gravity Camp 6L
Best Collapsible Bottle Filter
Are you going out for a long day in the hills? The Katadyn BeFree is a personal soft hand bottle that fits a high flow filter with a short length inside. Scoop water on-the-go and drink straight from it. It'll filter as you drink, fueled by a soft squeeze and your sucking force. The soft bottle top is adaptable to other narrow bottle tops, making it reusable if it happens to spring a leak. Because the filter is short and the bottle is collapsible, you can roll it up to the size of your palm and stow.
The biggest issue with this product is the durability of the soft bottle. We have had this bottle spring leaks on us pretty consistently over the last five testing periods. So it's not durable. However, since it is adaptable to other bottles, it can be used over and over again. It also only holds 0.6 L of water and can't be used for large storage, so water sources need to be plentiful.
Read Review: Katadyn BeFree
Best Chemical Treatment
Aquamira Water Treatment Drops
If you've got time to wait, the Aquamira Water Treatment Drops is a lightweight and inexpensive travel system that is used by many thru-hikers. Treatment is simple: activate the substances, then drop it into your water and wait. Of all the chemical treatment systems, it kills the most stuff, including finicky cryptosporidium cysts. When doubled with a filtration system, it can easily be used anywhere in the world.
Unfortunately, chemical treatment doesn't filter out particulates, so we'd recommend carrying a pre-filter or a handkerchief to do that work. While it's advertised that treatment time is just 15 minutes, which will kill most stuff, you have to wait much longer (four hours!) to get rid of hard-shelled cryptosporidium cysts, a protozoan found in North America. Also, this will leave a slight taste in the water. But, either as a backup to a filter system or a primary treatment system, these drops are our favorite chemical treatment.
Read Review: Aquamira Water Treatment Drops
Best UV Bottle Purification System
The CrazyCap uses a UV light to sterilize surfaces from viruses, bacteria, and protozoa. The system uses a USB charge cable to charge up this bottle cap (that is compatible with some other bottles), so maintenance is easy and without hassle. Simply press on the top twice to purify the water you've collected in the bottle, and get 0.5 liters in just 60 seconds. This is a system that can easily be used while hiking, traveling abroad, or around the house. The UV cap can even be used to sterilize surfaces around the house for potential viruses and other infectious agents, which some might consider a huge advantage. If you seek a simple purification system that'll protect you from water sources that are contaminated with E. Coli, Viruses, Protozoa, or other microscopic creates, this is a lightweight and simple one to consider.
While this system is quite nice, we've got to say it's hard to trust that a UV light is actually working to destroy viruses. It almost seems magical and takes some trust. Aside from that, this is not a filtration system, don't expect it to get rid of particulates in the water. It also doesn't protect from chemicals, pesticides, or heavy metals, so don't go scooping up water where these could be present. This self-contained UV light water purifier is super convenient though in its intended environment.
Read Review: CrazyCap 17oz
Best for Turbid Water
MSR Guardian Purifier
The MSR Guardian stands out for its exceptional ability to purify water of water-borne viruses, unlike other hand pumps on the market. The hollow fiber filter has a huge lifespan (which presents a great value) and there's no need for maintenance. It's built to last, it's tough, it's strong. Its flow rate is exceptional for a pump filter (about 37 seconds for one liter) while the backflush system makes it functional even in the sludgiest of stagnant or turbid water holes. We have been testing this pump for over five years, and it still hasn't failed us. It can be frozen which makes it a good option for camping in cold conditions. It's also the only system that actually performed well in turbid water, which is completely rare and hard to find. Take it with you internationally, to the Grand Canyon, or on a canyon trip.
While this purification system is quite incredible, it's not for everybody. The initial price tag is immense and quite frankly, most people aren't willing to pay. If you're looking for a pump filter that'll do work here in North America, you probably don't need this Cadillac of hand pumps, a normal hand pump will do. It's also quite large and bulky which adds a chunk of weight to the pack. But, if you're seeking the best pump that will hang with you for years of service, this is the one.
Read Review: MSR Guardian Purifier
Large Capacity for Groups or Basecamps
MSR AutoFlow XL
The MSR Autoflow XL is a gravity backpacking water filter designed for large group use and basecamps. Its large capacity can hold up to 10L of water, with an adaptable design fitting many different storage vessels. This is our favorite for group use simply because it requires very little set-up and can be left unattended while filtering large quantities of water. It also doubles as a hand-wash station or even a shower during the warmer seasons.
While we do love this system, it offers the slowest flow of any gravity filter tested. The filter needs consistent backflushes, especially when dealing with turbid water. As long as users know and accept this fact, it's a fantastic large group option. In addition, a stable tree or hanging anchor point must be able to hold 22 lbs of weight, if you're planning on using it for its whole capacity.
Read Review: MSR Autoflow XL
Best Value Hand Pump
The Katadyn Hiker is a reliable pump filter that's one of the best selling on the market. The pump-action system collects water while you actively pump it through the device into your water bottle. It works best with a wide-mouthed container (i.e., Nalgene bottle) and also has a hydration bladder compatible attachment so you can fill up hydration bladders with ease. This mid-range pump is fast, smooth, and easy to use. It's one of the most consistent in its performance, offered at a great price.
Like any filtration system, we have a few caveats. If this thing clogs up completely, you can unscrew the housing and attempt to clean it out, but a full replacement of the cartridge is advised by the manufacturer if this occurs. The filter can't be frozen, and it absorbs water. In addition, there are some durability concerns. Several users have noted that a small plastic piece that attaches the inlet hose break off when on-trail. We didn't have this experience, but our advice is to never pump with the system on the ground to avoid this from happening. If you're looking for a hand pump, this one is most likely to get the job done and save you significant cash.
Read Review: Katadyn Hiker
Best Bottle Press Purifier
The Grayl Geopress quickly turned into one of our most used and favorite purification systems. In comparison to the rest, it supersedes most systems for a variety of reasons. It's easy to collect water, push it through the system, and drink. More importantly, this water purifier removes the most disgusting water contaminants that you would find. Not only including viruses, but also heavy metals, plastics, pesticides, and more. No other system we tested can do this. The bottle is pretty durable and you can get a mouthful of water in seconds. Save yourself from buying tons of water bottles when you travel and get this instead. You can gather water from essentially any polluted source and trust in its water quality.
In comparison to the Grayl Ultralight system, this bottle is much easier to push down, especially with the handgrips along the side. While we appreciate the use of this system, it's also definitely not our first choice for lightweight travel in the backcountry. While some users do use it as a bottle for backpacking, its heavy and bulky design is a bit much, and it doesn't filter large quantities of water quickly. It also presents a relatively poor value for the price. The cartridge life is low and the refills are pretty expensive. But for traveling, especially in urban areas abroad, we think the Geopress has a lot of peace of mind to offer.
Read Review: Grayl Geopress
Why You Should Trust Us
Jessica Haist and Amber King are seasoned gear testers (over 14 years of collective experience) that love to explore in the backcountry. Both are from Toronto, Ontario, and both work in outdoor education. As educators, they spend lots of time in the woods, backpacking along trails and exploring remote locations. Jessica lives in California, where you can find her playing at the local granite crags, sucking up rays of the sun, or riding trails on her mountain bike. Amber lives in Colorado and is an avid ultrarunner and rock climber. Fastpacking and backpacking are her two ways to explore the remote and high mountains of the San Juan Rockies, right from her doorstep. Both use backpacking water filters for work and recreation regularly.
In our testing, we ran and walked hundreds of remote trail miles, glugging gallons of water filtered and purified from some questionable sources. We test each product through an unbiased lens. We assess the anatomy of each system, dissect the pros and cons, and evaluate whether or not a system is reliable enough to earn our favor. Each product sees both hands-on, in-field experience, with at least a week or more on the trail. We also perform rigorous indoor tests to determine minute differences between products. Our recommendations come from experience in the field and home-based experiments that comparatively test the performance of each product.
Analysis and Test Results
Great backpacking water filters or treatment systems will keep you healthy while embarking on missions that lead you into remote areas. Whether you're traveling abroad or adventuring deep into the woods, this piece of gear is a must-have for any backpacker. We tested a wide variety of water filters and purification systems and rated each on six metrics. This article compares the different options within different categories such as hand pump filters, UV purifiers, gravity filters. We recommend you think about what kind of filter you want first, then read about our in-depth comparisons. If you don't know, though, that's fine too, and we can help. We hope our in-depth research and review helps you find the best gear for all your outdoor ambitions.
A great purifier or filter is one that lasts a long time and doesn't cost an arm and a leg to maintain. While the original ticket price on some items might seem really low, in the long run, the expenses might add up, running up a bill in the long run. To take a critical look at value, we took the time to calculate the cost per 100L of water for each filtration system. We also look at the cost per 100 liters for the refillable filter cartridge. By looking at this data, you can see which systems offer the best upfront and long-term value. Of all these systems, the Sawyer Squeeze systems (our Editors' Choice for personal use) and the CrazyCap (our favorite UV purification system) offers the best value. Both offer more filtered or purified liters before needing replacement than other models we tested.
Of the gravity filters, the Katadyn Gravity Camp offers a low upfront cost and a low maintenance fee, and a good option for larger groups. The Katadyn Hiker Microfilter is a pump filter with a low upfront cost as well with great reliability and longevity for the single hiker. Both also earn our Best Buy Award. While purification tablets and liquids like the Potable Aqua Drinking Water Germicidal Tablets and Aquamira Water Treatment Drops have a super low upfront cost, they actually offer a lesser value per liter as they need to be replaced every 30 liters or so. When considering the price, consider how you'd like to pay for your system — either with small, repetitive costs, or a larger sum but much less frequently.
When considering this metric, we specifically look at what the backpacking filters can get rid of and the overall taste or odor of the water. We went to shallow puddles, smelly swamps, and pristine streams to see what each could do. Those that remove everything including heavy metals and pesticides triumphed in this category.
Backpacking water filters and purifiers use different types of technology to remove viruses in addition to protists, bacteria, and other water-borne pathogens. Filters typically don't have a pore size that can remove viruses. Other categories are chemical tablets and UV light systems. Below, we outline the different types of purifiers and filters out there and what they are capable of eliminating.
Water purifiers are what you need if you're traveling abroad or treading in terribly polluted areas. Water purifiers remove particulates, protists, and bacteria, but can also rid the water of viruses. For example, the MSR Guardian is a tried and tested hand pump purifier that can do just that. It can expunge smells from water and remove viruses, but it can't remove heavy metals or chemicals from water sources. That said, if you're traveling internationally, it's a great companion to pump water from the sink or collect from a local stream.
The Grayl Geopress stands out above the rest because this water bottle purification system uses push technology to scrub water of everything that might contaminate it. We tried this on a particularly contaminated stream in Ouray, Colorado that runs yellow from pollutants like lead, arsenic, chromium, and iron oxides. The water smells acidic and is acidic. After using the purifier, it took all these metals out and neutralized the pH of the water, which amazed our testers. We drank it shortly after, not noting any weird tastes or side-effects. The Grayl Ultralight provides the same level of water quality as well but is much more of a pain to use. This is a filter we'd trust taking water from any source, whether you're traveling to Africa, Thailand, India, or anywhere abroad. We'd also take the MSR Guardian with us, but we'd be more careful about where we get our water from. That said, the MSR Guardian has a much longer lifespan and can process more water in bulk, where the Grayl can only process 750mL at a time.
The Aquamira Frontier Max is a unique in-line purification system that removes viruses and other contaminates. It can be attached to a hydration bladder hose, gravity filter, or used on its own to provide water purification. So instead of filtering your water and drinking it, you suck it through the filter. It also has the ability to remove all the substances that you can think of. A good option if you don't like to pump or press water. The only issue is it takes quite a bit of sucking power.
UV light purifiers also effectively eliminate water pathogens. Imagine sitting on a beach in Mexico with a tequila-infused beverage with ice. Unsuspectingly, you get sick. Why? Ice is typically a huge source of sickness for travelers as it carries bacteria. UV light like the SteriPEN Ultra, a UV purifier can be put into the glass and swirled around to destroy pathogens that could cause an infection. We tested two UV purifiers in this review, the SteriPen and CrazyCap. Both are easy to use. The SteriPen is a long structure that you swish around in your water while the CrazyCap is a lid with a UV light built into the bottom, so purification happens inside the bottle. Both offer the same water quality level. Unfortunately, UV light purifiers won't remove particulates, smells, or metals and don't score as high as other purification models because of this.
The Aquamira Water Treatment Drops is our favorite chemical treatment. It can kill most microorganisms but does impart an off-flavor to the water. In addition, they can't filter out particulates. The Aquamira drops are the best because they kill all organisms (with enough time) while the Potable Aqua Iodine Tablets and MSR Aquatabs can only destroy viruses, bacteria, and some protozoans, but not Cryptosporidium. The active ingredients in these treatment cannot get rid of Cryptosporidium as the drops do. Also, the drops have the least "chemical" taste of all three options, which scored by points among our testers.
Water Filtration Units
A backpacking water filter (not purifiers) can remove particulates, bacteria, protozoans (giardia & cryptosporidium) but cannot remove viruses. The best filtration systems can remove chemicals, heavy metals, and odors using activated carbon embedded in the core of the media.
Of the backpacking water filters, the Katadyn Hiker Pro, Katadyn Hiker Microfilter, MSR Miniworks EX, and Lifestraw Universal offer protection from both microorganisms and chemicals like pesticides to improve the taste of the water. The LifeStraw Flex can remove lead which is a unique property, and a great option if you're worried about lead in the water source.
Filters that utilize a hollow fiber filtration media, like the Platypus GravityWorks and the MSR Autoflow XL, are plentiful in this review. If it doesn't have a carbon core, don't expect it to improve the taste of water or remove chemicals. These two gravity filters, for example, cannot remove these contaminants.
A Note on Water Turbidity
It's essential to plan for water sources that might be saturated entirely with silty sediment (called highly turbid). For example; the Colorado River that has carved out popular backpacking locations like the Grand Canyon is one of the most turbid rivers in the world. If you live close to it, you've seen it transform from a clear greenish color to what looks like chocolate milk shortly after rainfall.
Most backpacking water filters and purification systems cannot deal with the amount of sediment and silt in water sources like this. The only system that held up in these conditions is the MSR Guardian Purification System, another reason it's one of our favorites. It utilizes an auto backflush that cleans the filter with every pump.
If you plan on traveling to areas with high turbidity, bring a gallon ziplock bag or a bag designated for settling water. Scoop up the silty water and let it settle for a few minutes. Clearwater will remain in the upper column, with sediment falling to the bottom. Decant the top water layer off into your filtration device, or filter from the top of the bag. This is an easy and cheap "pre-filtration" technique for these areas. Some gravity systems have a "sediment collecter" in the bottom, like the MSR Autoflow XL.
Durability and Maintenance
Reliable backpacking water filters are durable in construction. You don't want to be without a filter simply because it gets dropped. You also don't want to spend hours maintaining it. 21st-century products are available that offer high quality and reliable with minimal durability.
The most durable and reliable products are chemical treatments. Each comes in either jars or prepacked packets that can go into a plastic bag. They have no moving parts, don't require maintenance, and don't expire. If you want 100% reliability, this is it. The Aquamira Treatment Drops is a favorite of ours. We would strongly recommend carrying these as a backup system, especially when traveling into the backcountry for extended periods of time. There are too many situations where filters can clog, parts might be lost, or things may not work. Carrying these treatment drops can mean the difference between life, death, and grave discomfort.Gravity Filters
Of this group, the Katadyn system seems to be one of the best constructed. The bag, unlike the Platypus and both the MSR systems, seems to be far more resistant to punctures and has a lot less going on. The Platypus is made of a strong plastic composite that could come apart at the seams, while the MSR is made of a more rubberized plastic compound. Of all these systems, they all seem very durable and reliable, with the Katadyn being the best.
All of these systems have filters that require frequent maintenance and care, depending on how much sediment is in the water you are filtering. Both the Platypus and MSR systems use the same hollow fiber technology. It's important to know that regular back flushes are required, which is simply flipping the filter upside down and allowing water to run through it. Alternatively, the Katadyn requires a rinse and has more moving parts, which is hard to clean with water that isn't clear of sediment in the first place. All systems are pretty durable and easy to use, just be sure that you're amenable to their maintenance to retain optimal flow.
Of the three, the Katadyn is the only one that can be used after it's been frozen. Given the filter's internal glass fiber construction, the filaments aren't destroyed when frozen. While it can't filter water when frozen, it is still usable after thawing out! If you're seeking a gravity filter that'll do for a winter camping trip, this is it. That said, it's not freeze-proof! That'd be an amazing innovation.Hand Pumps
These models are pretty durable in general until they get clogged. The MSR Guardian is the most durable and maintenance-free backpacking water purification system that we'd trust anywhere. It auto cleans, even in turbid water, offering the best reliability in terms of hand pumps. It can also be frozen, unlike any other hand pump system. The MSR MiniWorks EX is another reliable hand pump. It uses a ceramic-carbon core that can easily be serviced in the field. Unfortunately, it does require a lot of maintenance to keep it working well (lots of scrubbing), but it can be fixed in the field.
The Katadyn Hiker Pro and Katadyn Hiker models are two of the best selling models on the market. Both are extremely consistent in performance. Both use a glass fiber filter that, if you allow it to become completely clogged, needs to be replaced. Both can be serviced infield, but you must be careful not to keep pumping if performance decreases. Between the two, the Hiker Pro is better by a hair. It's more durable and performs a bit better. For the minimal improvement, though, we tend to recommend the Hiker. These pump filters require less maintenance than the MSR MiniWorks EX.
The MSR Hyperflow is the fastest flowing pump filter tested, but also requires the most service. The filter, when clogged, can only be backflushed. In order to do that, you need to take the system apart completely. It requires regular backflushing (every 8L in clear water, more in turbid), and is a bit of pain. It's a durable unit but requires quite a bit of care.
We are super impressed with the Sawyer Squeeze, lasting up to 10,000 gallons and pretty well built-in nature. Sawyer offers three systems, the regular Squeeze, Mini, and Micro. With all these systems, the bags breaking when in "squeeze" mode are the most annoying. When squeezed too hard, the bags break at the seams, with the Mini being the most problematic of them all. The regular Sawyer offers a good amount of flow, with less squeeze-force required, breaking fewer bags overall. All of these systems do require you to carry a plastic syringe to backflush after most uses. Overall, the regular Squeeze requires the least maintenance simply because it's a bigger squeeze system than the rest.
Another great squeeze bottle is the Katadyn BeFree 0.6L, our favorite option for lightweight missions like trail running. The bottle that it comes with is also prone to leaking. However, we found that it can be attached to other hand bottle options that are much more durable. Overall, its durability is a drawback, but the filter itself offers some of the best flow and adaptability. To clean, simply swish it in clean water. You don't need to carry any extra parts and clogging does not happen often.
The Sawyer Squeeze and Lifestraw Personal Water Filter are two options that we really like. If you're seeking the most barebones option that doesn't require you to carry extra items, the Lifestraw is where it's at. It's light, easy to carry, and long enough so you don't have to get your face into water sources. Both the Squeeze Mini and Micro are fine options for on-the-go carry, but require you to still carry a syringe and straw adaptor.UV Light
This is one of the most unreliable systems simply because it needs a power source. Battery life can be tough to predict, especially in colder temperatures. The CrazyCap earns a higher score than the SteriPen here because it's completely waterproof. It also requires less time to charge overall. One charge lasted us about 30 liters but only took 1.5 hours to charge completely. After testing it for months, it was consistent. Neither are units we'd completely trust on a long backpacking trip, but both are suitable for travel or purifying municipal water sources on a regular basis.
In this metric, we consider how quickly you can get water from the source to a filtered state. To test this, we noted if water filtration is instantaneous. If not, we performed three separate time trials and averaged them to determine an average time to filter one liter. The fastest times did best in this metric.
The most immediate backpacking water filter systems are the straw filters that you can drink through immediately from a water source. The Aquamira Frontier Max and Lifestraw Flex are a few of our favorites. Water flow is typically slower but very much based on the construction of the input, filter body, and straw or bite value. For example, the Lifestraw Flex and Aquamira Frontier Max have comparable flow rates, not requiring as much effort as the laborious Lifestraw Personal Straw.
These backpacking water filters use a collapsible bottle or pouch, offering a little water storage. The Sawyer products all demonstrate this adaptability, but our favorite is the Katadyn BeFree for its fast flow bite valve that delivers water quickly. This makes it a favorite among trail runners because water collection takes no time and treatment is instantaneous.
Of all the Sawyer products, the Sawyer Squeeze offers the best flow rate. It can filter a liter of water in just 40 seconds when in squeeze mode. The Mini, the smallest of the group, takes 2 minutes to filter a liter of water, with the Micro somewhere in between. If you like the Squeeze products and want one with an awesome flow rate, the Sawyer Squeeze is the way to go.Pump Filters
We pumped over 40L of water, timed it, just to see how many strokes each took, and which were the fastest. The hands-down winner in this category is the MSR Hyperflow (27 seconds, 29 strokes per liter). It pumps out hoards of water super quickly. However, this model was also the quickest to slow down, reducing its flow rate significantly as the liters added up. The MSR Guardian Purifier placed in second, filtering a liter in 37 seconds, and maintaining performance in even the murkiest of water. The other pumps followed as such — the Katadyn Hiker Microfilter (42 seconds, 52 strokes), then the Katadyn Hiker Pro (53 seconds per liter), and lastly, the MSR MiniWorks EX (80 seconds, 90 strokes per liter).
The Katadyn products and the MSR Guardian offered the most consistent performance overall, with these working best in Turbid conditions. The MSR Hyperflow and MiniWorks EX needed cleaning almost every 4L in these tests. In our sludge tests, all the pump filters needed to be cleaned out every liter, except the MSR Guardian.Gravity Filters
Comparable in the rate of flow, gravity filters are nice because you conveniently don't have to pump or do anything once they are set up. They can process large quantities of water, making them highly effective for small to large groups. All of the gravity filters are super close in treatment time.
The Platypus Gravity System is the fastest, filtering one liter in 52 seconds. The Katadyn Gravity Camp filters one liter in 64 seconds. The MSR Base Camp is close behind at 69 seconds. Lastly, the MSR AutoFlow XL took just around 2 minutes per liter, making it the slowest gravity filter tested. While gravity filters are inherently rad because there's so little work involved, there are some stark differences in performance. Please note that these flow rates will decrease with murkier or turbid water, and if the filters are not properly maintained. Also, note that if you aren't rushing, the difference in passively waiting one or two minutes for a liter of water to be filled often isn't a big deal.
Weight and Packability
Weight and packability are important. If you're carrying less weight, long hikes can be more enjoyable. To assess this metric, we weigh each system and look at its relative profile. We tested them with hydration vests, backpacking backpacks, and regular packs. The lighter and easier to pack and store, the better the score.
Of all the treatments out there, chemical treatments are by far the lightest. If you're planning a long thru-hike or huge trail run, they're a great choice. Of the treatments, the MSR Aquatabs and Potable Aqua Drinking Water Germicidal Tablets can simply be put into a little baggy, without requiring you to carry the whole bottle. This helps to eliminate weight. The only downside is both of these results in a chemical taste in the water (for most people). The Aquamira Treatment Drops can't be parsed out like the tablets, but some people prefer them because they don't taste as bad as the tablet options out there.
The lightest filtration systems out there are on-the-go systems like the collapsable Katadyn BeFree and Lifestraw Personal Filter. The lightest purifying on-the-go filter system is the Aquamira Frontier Max. Of the gravity filters, the Platypus Gravityworks is the lightest and most packable (11.5 oz). If you prefer a hand pump system, the lightest systems are the MSR Hyperflow (10.6 oz) and the Katadyn Hiker Pro (13.2 oz).
Ease of Setup
We measured ease of setup based on how intuitive backpacking water filters are and how many steps each one requires to set up. We also consider how easy it is to access different water sources.
The easiest set-ups are the ones that require little thought and easy access. No parts or steps to follow. On-the-go systems prove to be the easiest here. The basic Lifestraw is the best for this. This filter, unlike other more complex on-the-go systems, requires you to find a puddle or accessible water source and simply drink.
Purification Tablets are also pretty simple. Those like the MSR Aquatabs and Potable Aqua Drinking Water Germicidal Tablets require you to drop them in the water and wait. The Aquamira Water Treatment Drops are also pretty simple, but with a steeper learning curve. These require you to follow a series of specific steps where you have to mix two solutions, then wait different periods of time depending on what you need to eliminate from the water.
Hand pumps are also relatively easy to set up and offer great access to all sorts of water sources. The Katadyn Hiker Pro, Katadyn Hiker Microfilter, and MSR MiniWorks EX are favorites because the intake can grab water from the smallest nooks and crannies. The MSR Guardian works well for this, but it has a larger particle screen that makes it harder to reach shallow sources. All pump filters are good for reaching water over steep banks, boat sides, or fast rivers when water access can be an issue.
Gravity filters require more effort to set up because you need a place to elevate them. In some cases, you can put it on a rock on a slope and that'll do. In other scenarios, you need to hang it. They typically earn a lower score in this category. Reservoirs that are very flexible with large openings. like those found in the Katadyn Gravity Filter, can get water from most water sources. However, because you have to scoop up water, the source needs to have a sufficient pool to collect water. Shallow pools are harder to reach.
Ease of Filtration
In the ease of filtration metric, we look at the amount of effort required physically to get water through the backpacking water filtration system. While we don't score storage capacity, we note how much water each system is designed to store or not store.
Of all the categories, both the SteriPen Ultra and CrazyCap require the least amount of work. Simply fill up the bottle and turn the light on! The SteriPen requires a little less time to filter a liter in comparison to the CrazyCap. However, we appreciate that the CrazyCap is completely hands-free and you can walk away from it while it works.
Gravity backpacking water filters are by far the best systems when it comes to ease of filtration. As soon as it's set up, the process is completely hands-off. All gravity filters in our review earn top points, all being easy to filter. These filtration systems can move lots of water quickly, making them a top choice for groups. One difference is the height requirement to filter. The Katadyn Gravity works needs full suspension and can't be put on the ground while the MSR BaseCamp, MSR Autoflow, and Platypus Gravityworks can be laid on a hill or over a rock and still filter water.
Some come with "clean water" vessels like the MSR Basecamp and Platypus Gravityworks while others like the Katadyn and MSR Autoflow have a simple hose running from the bag to a storage vessel of your choice. All prove to adapt nicely with a hydration bladder and can be filtered into a bottle if needed.Hand Pumps
Hand pumps are a little harder to use as you need to physically pump to move water through the system. This can be harder if the filter becomes clogged, and the output is different for each hand pump filter. Of the hand pumps we tested, the MSR Hyperflow and MSR Guardian are the easiest to use. Both have high output which means you have to pump less and get more water. The Guardian has a large handle that's easy to grab, similar to the MSR MiniWorks EX. The MSR Hyperflow has a tinier system, but it's still pretty ergonomic. All hand pumps we tested have attachments that fit a Nalgene bottle best. The Katadyn Hiker models both have easy to use handles, but they aren't as ergonomic as the MSR products. These also require more pumping to get more water. The MSR MiniWorks EX took the most work per liter of all the hand pump filters.
On-the-go backpacking water filtration systems are typically easy to set-up but are propelled by either sucking or squeezing forces. Of the on-the-go systems, the Katadyn BeFree, Sawyer Squeeze, and Aquamira Frontier Max are the easiest to suck through when in straw style. Others are harder, like the Sawyer Mini that gives you very little water for each suckle. We also love the Lifestraw Adaptor Kit that allows you to turn a personal water bottle into a filtration system.
These systems don't offer much when it comes to water storage, however, they are adaptable. For example, Sawyer products come with a storage pouch that you can use to store water. Though, if you don't trust these bags, you can find a hydration bladder, a suitably-sized collapsible bottle, or even a regular water bottle that is compatible to use instead. You can also simply carry a "dirty Nalgene bottle" and drink through the on-the-go filters through that. Just make sure you don't drink from that vessel on the trail, or you might suffer the effects.
The Katadyn BeFree bottles have a few different sizes and are compatible with other soft bottles that offer better durability and flow. But for the most part, they are designed to be carried when water sources abound. Either that or you can fill up a "dirty bladder" and carry it around with you, drinking on the go.
There are a lot of different backpacking water filter options out there. Ultimately, you need to figure out what you need for weight, packability, and water quality. Before you go anywhere, be sure to research the water sources and what kinds of pathogens you may contact. It's also not a bad idea to carry a chemical treatment as a backup, especially on long thru-hiker. Cheers to clean water and many adventures ahead deep into the backcountry.
— Amber King and Jessica Haist