The Best Backpacking Water Filter and Treatment Systems
What is the best water treatment system for backpackers and campers? To find out, we tested 15 of the best, latest and greatest backpacking water filter systems and compared them in detailed head-to-head tests in this extensive review. With more and more manufacturers coming out with their own versions of gravity filtration units, the results are no longer shocking, given all the new types of filters on the market. Both the Best Buy winner and Editors' Choice are not traditional pump systems. Read on to discover what is best for your outdoor adventures.
Read the full review below >
Test Results and Ratings
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Analysis and Award Winners
Best Overall Water Filter
Best Bang for the Buck
Top Pick for Ultralight
Aquamira Water Treatment Drops
Top Pick for International Travel
MSR Guardian Purifier
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Analysis and Test Results
The human body is about 60-70 percent water by weight. The amount of water a person needs per day varies depending on the temperature, humidity, altitude, and the amount of physical activity the person is engaged in. At rest, the Mayo Clinic estimates men need about 3 liters of water a day and women need 2.2 liters. But if you are exercising in the mountains, that may increase by 50 percent, to over 4 liters for men, and more than 3 liters for women. At a weight of 2.2 lbs per liter, most of us don't want to carry enough water for a four-day backcountry trip in our packs (over 35 lbs for men, 26 lbs for women).
Fortunately, we can usually find the water we need in the backcountry from streams, lakes, snow run-off, or spring seeps. The problem is that backcountry water may not be safe to drink without treatment. Giardia, one of the more well known risks to backcountry water sources, is a protozoan parasite readily transmitted via the feces of deer, cattle, beavers, and other mammals. But, other contaminants, such as bacteria, cysts, and a particularly nasty protozoan called Cryptosporidium, are also risks in North American backcountry areas. And, internationally, virus contamination is not uncommon and one could encounter viruses like Norovirus/Norwalk, Rotavirus and Hepatitis A. The answer is to carry a backpacking water filter treatment device that can remove these contaminants, and simply cleanse water as you need it. Carrying a water treatment system is much lighter than bringing all the water you need. And with it, you need only carry enough water to get you from one source to the next.
Types of Water Treatment Systems
In this review, we examined 15 different backpacking water filter treatment systems to find the very best. Five different types of systems were represented:
Pump filters — These are very common, and what people usually think of first when they think of water treatment. These devices cleanse water by pumping it through a filter that has a pore size that is too small for bacteria and protozoa to move through. Example: Katadyn Hiker Pro.
Gravity filters — These products cleanse water by using gravity to push it through a filter, eliminating time-consuming pumping. Example: MSR AutoFlow Gravity Filter.
Filter Straws — These models treat water as you drink directly through a big straw, which doubles as a hollow fiber filter. Example: LifeStraw.
Chemical drops and tablets — Drops and tablets purify water by adding a chemical to it in order to kill all things living in the water. They have the advantage of killing viruses in addition to bacteria and protozoa. Example: Aquamira Water Treatment Drops.
UV light — These mechanical devices purify water by zapping it with ultraviolet light. This also has the advantage of killing viruses. These products require batteries and/or chargers to work. Example: SteriPEN Adventurer Opti.
Please refer to our buying advice article, How to Select a Backpacking Water Filter and Treatment System, for more detailed background information on the need to treat backcountry water, contamination sources, and the advantages and disadvantages of different types of water filter treatment methods.
Criteria for Evaluation
When evaluating various treatment systems, the most important factors we considered were reliability and effectiveness, because if your system doesn't work, then there is no use in carrying it. Also, different systems treat for different hazards, and it is helpful to know what your system will be treating for. We think that three of the criteria we evaluated for are equally important: weight, treatment capacity and ease of use. Weight is important because when traveling in the backcountry, it is desirable to have a compact and lightweight system and not to have a heavy and clunky filter weighing you down (or you are likely not to even bring it with you). We also evaluated how well each system can treat large quantities of water, so groups or hikers needing a lot of water at base camp can select an appropriate treatment method. Ease of use is becoming a more prevalent selection criteria for shoppers these days, and we agree that it is important. Filters no longer need to be cumbersome and clunky and there are some filters super easy to operate in this review. Next, we compared how long it takes the system to work before you can drink, (speed) and this was where we noticed a large difference between methods. Read on for more details and comparisons as well as a few other considerations.
Reliability and effectiveness are related, but are slightly different; there are a few different sub-headings that fall under this category.
Effectiveness : This measures what the treatment system actually eliminates.
Systems That Treat Viruses
If you plan to travel internationally where water sources have a much higher likelihood of virus contamination, a system that treats viruses is strongly recommended. Here is a quick look at six systems that do treat viruses:
All the other backpacking water filters remove bacteria, cysts, and protozoa like Cryptosporidium (which some of the chemical treatments do not eliminate); they also remove particulate (which many of the above treatments do not remove). Usually, protection against bacteria, protozoa, and cysts is all you need for hiking in the mountains of U.S. and Canada. Virus protection is generally considered a need for international travel.
Chemical and UV treatments typically remove viruses, bacteria and some protozoa, but not the sediment you might pick up from a particularly dirty source. So, you wont get sick from your water but it might taste bad or look icky.
Different water treatment methods are effective on different types of organisms. The main difference in effectiveness in the systems we reviewed is whether or not a system eliminates viruses or the hard-shelled (meaning hard to kill) protozoa Cryptosporidum.
Reliability is a measurement of how heavily you can rely on the system you are carrying, and if you are likely to need a backup system. We evaluated the durability of each unit based on the different components, resistance to freezing, how much maintenance is required and how easy or complicated the maintenance required is.
Simple pump systems like the Katadyn Hiker Pro and the MSR Sweetwater are easy to rely on. More complicated systems like the UV light purifiers are slightly less reliable because of factors such as batteries or bulbs dying. We found our most reliable systems to be ones where not many things can break or go wrong, so they are easy to depend on. The Platypus Gravityworks, Aquamira Water Treatment Drops, Sawyer Mini, and MSR Guardian all fill this requirement. The least reliable were the SteriPEN models due to reports of malfunctioning, and the somewhat short battery life, which makes us hesitant to bring them on multi-day trips.
The MSR Miniworks, MSR Guardian, and Sawyer Mini last quite a while before needing a replacement filter - they treat 2,000 liters, 10,000, and 100,000 liters respectively. The Sawyer Complete, according to its specs, can last for a million gallons, which is a lifetime of water treatment. The Katadyn, MSR and Platypus gravity filters all last for 1,500 liters. All of these are long-lasting, reliable options. The filters with the shortest lives are the Katadyn Hiker Pro and the MSR Sweetwater, which treat approximately 750 liters.
Systems that had reported issues of durability were the SteriPEN and the Katadyn Vario. One pair of hikers said the SteriPEN was ruined after getting rained on (although the new Ultra is watertight), and other users reported random malfunctions and glitches with the light unit. The Vario has been reported to leak heavily from between the filter casing and the pump housing after heavy use, though we did not observe any of these problems with either model.
Ease of Use
We measured ease of use based on how intuitive each system is and how many steps each one requires to set up and treat water. We also considered the frequency of maintenance and the complication of the back-flushing process.
The chemical systems require no maintenance whatsoever, and typically involve adding to water and waiting. It doesn't get much more simple than that.
The Sawyer Mini is one of the easiest backpacking water filter systems: fill up your bottle and drink through the filter. Similar to this one are the straw-filters like the LifeStraw, which allow you to drink directly from a stream or creek, or to collect water into a bottle and drink it through the filter later. The runner-up for ease of use is the Platypus GravityWorks. The process of filling up the dirty bag, attaching the hoses, and waiting for it to filter is very painless. It has an easy, one step back flush process that involves inverting the clean bag over the dirty bag with no complicated disassembly and you can walk away during the process. Likewise, the MSR AutoFlow is an incredibly easy to use gravity filter.
The Miniworks, Katadyn Vario and the Sweetwater lost points for having complicated maintenance routines. The Miniworks' maintenance is fairly intuitive - simply open up and scrape clean the ceramic filter - but this process, which also needs to be done fairly often, can be a pain and seems to be relatively frequent if you're using the filter regularly and for multiple people on a trip. The MSR Guardian has revolutionized pump filter maintenance – by having none. Instead the Guardian self-cleans with every stroke, expelling the dirty back flushed water out a separate hose – we think this is great and wish that every filter had this feature!
The SteriPEN Ultra is very simple to use: you push a button and the screen smiles at you when it is finished. The main concern with this purifier is that the batteries need to be monitored and charged frequently.
Thankfully, in the new models we have tested there is a trend towards ease of use and little to no maintenance.
Depending on how frequently you travel into the backcountry or how many people you need to treat water for, you will likely want to consider how much water can be treated by your chosen water filter system. Once again, different methods have different limitations.
Pump filters allow for a seemingly endless amount of water. You can pump as much or as little as you need. All filter units need to be replaced eventually, but for the short-term, these allow for clean water for a single person or a group for multiple days on end. All you need are some bicep muscles and time to sit and filter into multiple vessels.
Chemical treatments are not as cost effective for long-term or large capacity use, but are light and easy for personal use. You can spend $15 on drops or tablets, and that leaves you with a limited number of liters to be treated; for instance a package of the MSR AquaTabs treat 60 liters for $13. Then when the chemical runs out, you need to buy more.
UV purifiers can only treat one liter at a time. This works just fine for immediate drinking needs for one person, but for large groups of people or treating water at a camp, the process becomes slow and annoying.
Straw filters have a similar limitation. They can be an excellent choice for personal use, but since they only filter water as you drink through it, they do not work for groups or camps. With the Sawyer Mini, one can filter water for others and into different vessels but it requires you to fill the provided soft bottle and manually squeeze the water through the filter into different containers. We found this process slow and cumbersome and prefer to use the Mini to drink directly out of.
Gravity filters excel at treating water for groups of people. They usually include 2L to 6L bags, and can quickly treat this amount of water at once. It takes under five minutes for the Platypus GravityWorks to treat an entire four liters. These backpacking water filters are ideal for groups and trips that involve a basecamp, since they also provide a way to store water and have it at the ready for cooking.
Imagine this common scenario: You are backpacking and come to a stream crossing where you can refill water. Your next water source will not be for another six miles, so you need to maximize this source. Ideally you will drink a good amount of water now, and fill up all of your bottles and/or bladder reservoirs now to carry with you to drink until the next source. This is when the time it takes to treat water really matters. Aquamira drops, our lightest system, takes up to an hour to fully treat for everything including Cryptosporidium. This chlorine dioxide system kills most pathogens in the first 15 minutes, but that still requires a wait time that cuts into precious hiking hours.
The most immediate systems are the straw filters, the Lifestraw, and the Sawyer Mini where you can drink directly through the filter. However, the water flow through some of these filters is slow and you can't carry very much water with you unless you decide to dedicate a vessel to carrying dirty water.
Most pumps can filter a liter in a little over a minute, which is preferable, and they can treat unlimited amounts of water, unlike the systems that are limited by a specific bottle or container. The Katadyn Vario was the fastest pump system followed closely by the Guardian.
The fastest systems actually surprised us: the Katadyn Gravity Camp 6L filtered one liter in 40 seconds, followed closely by the Platypus GravityWorks and the MSR AutoFlow, each filtering a liter a minute. At first we thought a gravity system would require the most waiting around, but in fact, they worked the quickest, taking one minute to filter one liter and 3:05 for an entire gallon through the GravityWorks. And better yet, you don't have to actually sit there and pump it, so you can fill it up and let it start working while you take a snack break or set up camp. We think that gravity filters are the bees knees and everyone should seriously consider owning one for their filtration needs. Even though chemical treatments are simple, the pump and gravity backpacking water filters are actually the best for a hiker on the go.
Weight is a huge concern since you will most likely be lugging your water treatment system with you on long hikes. Hiking is more enjoyable with less weight on your back, so wisely selecting a treatment system that does not weigh more than your sleeping bag is a huge plus. Rather than go by the manufacturers' specs, we weighed each system individually, including all the accessories and carrying cases that would be brought with them into the backcountry, to give you the most accurate idea of how much the system actually adds to your pack.
The lightest backpacking water filter systems are usually chemical treatments, which are compact and almost unnoticeable in your pack. Aquamira Water Treatment Drops weigh 3 oz with their carrying caps. If you only want to bring a couple individually wrapped chemical tablets, the MSR AquaTabs only weigh 0.2 oz for the whole package. The Sawyer Mini is also one of the lightest systems, rivaling the chemical treatments with a 1.6 oz weight for just the filter, proving even lighter than two full bottles of Aquamira. Next comes the LifeStraw at at 2.7 oz and the Katadyn Gravity Camp 6L at 11.5 oz. The heaviest and bulkiest systems were by far the the Katadyn Vario at almost 20 ounces and the Guardian at 22 ounces.
Once you've used a filter in the field it will unavoidably be heavier than when you started out, since it is very difficult to get all traces of water out of the filter. Unless you have all day to wait around for the filter to dry out, consider doing your best to try your filter out overnight to get all that extra water weight out. If you're in cold climates it's best to bring your filter into your tent so it doesn't freeze; while you're at it take it apart so it can dry if possible.
We did not specifically score the products in this review but still think this is something to take note of. Though taste is not a huge factor to consider when purchasing a water treatment system, there is a noticeable difference between certain treatment methods. The chemical treatments all change the flavor of water slightly. Iodine is famously horrible tasting, but the taste-neutralizing tablets do a fairly good job of counteracting it. Chlorine dioxide does not add an entirely unpleasant flavor to water, but it has a small background, pool-like taste to it.
Many filters actually improve the taste of water by cleaning out chemicals and heavy metals and neutralizing odors like the Vario. The SteriPEN is the one system that doesn't change the flavor at all, positively or negatively.
For comparison's sake, we did the math for you for the most cost effective methods:
Some water treatment systems offer a pre-filter option such as the SteriPen Water Bottle Pre-Filter which helps get large particulates out of the water to make sure the light penetrates to all of the water. The MSR Sweetwater Prefilter filters out the particulates before it reaches the filter to help keep it cleaner for longer.
History of Water Filter and Treatment Systems
A brief history of water treatment leads to a better understanding of the current methods for filtering and treating water in the backcountry.
In the early 1970s, the Clean Water Act (CWA) was passed in the United States as a response to contaminated water sources and the need to protect fresh drinking water for human consumption. Water safety concerns sparked a new era of water filtration and purification on the municipal level. Coinciding with the implementation of the CWA, reports of backpackers becoming ill from streams and lakes initiated backcountry water treatment development for the public; it was around this same time period that hikers and backpackers learned of Giardia in trailside water sources.
Up until this point, backcountry travelers rarely, if ever, experienced illness from drinking water directly out of streams, lakes, or rivers; the "Sierra Cup" refers to dipping a cup straight into the water and then drinking it with no treatment. The need for backcountry water treatment resulted from unsanitary practices such as people not washing their hands after going to the bathroom or from stock defecating near or in water sources. Over time, these practices have impacted the clarity and purity of backcountry water. Present day issues revolve around these same sanitary issues and have grown to include soaps and food particles in streams, rivers, and lakes.
Backcountry water filtration was born from centuries of water treatment history. Boiling water for improved taste dates back to 2000 b.c.e. It is believed that this method of water treatment was solely for better taste; water impurities had not yet been related to human illness.
Centuries later, Hippocrates is recognized for relating water to health by means of the "four humors." Rhe four seasons balance with the body's "four humors" for equilibrium in temperature, Uf you had a fever, a cold bath could balance your temperature to wellness, etc. He is also known for the Hippocratic Sleeve - the first filtration method ever recorded. It was water poured through a cloth bag, after being boiled, to capture sediment or debris, thereby purifying the water.
Aqueducts of Rome and Greece as well as Mayan cultures created the first municipal water sources but these had less influence on filtration and purification and greater influence on transport.
Sand filters were the first effective form of municipal water treatment through France and other regions of Europe. The goal was to provide safe, clean drinking water and bathing water to every household. From the mid 1700s to the mid 1800s, municipal water plants were developed with slow sand filters that physically blocked the passage of contaminants as water moved through.
In 1590, the discovery of microscopic glass offered a magnified look into water droplets. Hundreds of years later, the ability to look at water on a microscopic level allowed the correlation between cholera and poor water quality to be made. This correlation also confirmed that clear water does not equate to pure water. Although sand water filters were mandated throughout London as a response to the cholera outbreaks, the use of chlorine to purify water gained greater attention on a global scale. Chlorine significantly decreased deaths related to poor water quality and water borne illness. Chlorinated drinking water was the most effective at assuring public health; it has been used in municipalities worldwide and has also had a relatively brief presence in the backcountry. Chlorine tablets, or halazone tablets, were even used for water purification during World War II but were replaced by longer lasting Iodine. (Chlorine is considered a poison and is therefore not a recommended method for water treatment.) Potable Aqua iodine tablets were developed in the 1940s and, like many other portable water treatment options, were first used by the U.S. Army.
In the 1960s and 1970s, environmental initiatives began passing acts for clean water and clean air. Water treatment plants were mandated in the United States to assure clean drinking water. Backcountry water filtration evolved from this point forward as water purity and safety became a concern.
Backcountry travelers would treat water by boiling or chemicals (chlorine, iodine, etc) for many years before portable pumps and filters were utilized. In fact, boiling water is still an effective, although sometimes inefficient, way to purify water while backpacking and traveling. Portable water filtration is fairly recent, with a presence in the backcountry for only the past few decades. Companies like Katadyn and MSR have had the greatest influence in modern water filtration systems, as we know them today.
In the 1930s, Katadyn developed ceramic water filters and over the next four decades would expand their water treatment technologies, such as UV, throughout municipal plants. It wasn't until 1999 that Katadyn's water treatment became available to the public. Prior to this, they manufactured water filtration systems for municipalities and military.
In the 1980s, military forces used Reverse Osmosis Water Purification Units, which could create potable water from a wide range of sources. The elaborate system involved polymers, cartridge filters, and high-pressure pumps to initiate and complete the process of reverse osmosis. The water would then be forced through a cotton filter to remove any sediment or particles and lastly would be treated with chlorine to preserve for later consumption. These initial systems were large but later became small enough for portability and hand operation; the hand pumping creates the pressure that the initial model created with a machine.
In 1991, MSR designed the WaterWorks filter for backcountry users by combining carbon and ceramic technologies; it fulfilled the need for portability and reliability in water filter performance. In the same year, MSR also brought the Dromedary Beverage Bag to market, providing renowned portability of water in the backcountry. The WaterWorks filter utilized a four-filter design: the first filter was a pre-filter made of porous foam and was intended to trap sediment, the next filter was a stainless steel screen that captured silt and algae, the third filter was designed of a carbon core and could remove bacteria and chemicals, and the fourth and final filter was pharmaceutical grade for sterile water - it was a membrane that removed any remaining bacteria. It became the most effective water filtration system for backcountry use. It was easy to field repair, easy to pump water through, was fast, and innovative; the filter could attach to water bottles and dromedary bags.
In 1994, a ceramic core was added to the original WaterWorks design. This core had small pores for better filtration, was easy to clean, and was better suited for higher output with large groups or challenging water conditions. The new design became further streamlined by removing the screen filter from the design (the second filter, as mentioned above). For the first time, carbon and ceramic technologies were combined for efficiency and ease of use.
In 1996, the MiniWorks came to market as a compact version of the WaterWorks filter. Both the WaterWorks and MiniWorks were upgraded from previous designs with a Marathon Ceramic element. The main difference between the two filters was the final membrane that added size and weight to the WaterWorks and made the MiniWorks more portable.
As of 1997, MSR has had an in house microbiology lab for assuring water purity beyond the standards set by the EPA.
The MiniWorks is a reliable water filtration system that is still available and popular today. In 2003, it underwent a facelift with the AirSpring Accumulator technology for even faster water pumping. An air pocket in the filter adds efficient to the reputable design that many backcountry travelers have come to depend on.
Water filtration continues to evolve with lightweight, efficiency, and ease of use in mind. In 2008, MSR introduced the Platypus CleanStream Gravity Filter; there are no moving parts, just hang and gravity efficiently does all the work.
Among the many manufacturers of water filtration and treatment systems, evolution continues to lean towards the greatest efficiency and portability as well as ease of use.
— Jessica Haist
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