For the dedicated prepper there are few tools more important than a quality backpacking water filter for your bug out bag. When prioritizing your needs in a survival situation, water is right up there with staying warm in rank.
We checked out the most popular water filters available to put together our list. Below you’ll find the ten backpacking water filters most suited for the modern prepper.
1. Sawyer Products Micro Filtration System
The Sawyer Products Micro is a pint-sized water filtration system designed to be the lightest and most portable filter on the market. It’s capable of filtering out 99.99999% of bacteria, including salmonella, cholera, and E.coli, and is also able to remove 99.9999% of all protozoa like giardia and cryptosporidium. Even better, the .1 micron hollow fiber membrane is incredibly easy to maintain and offers a working lifespan of up to 100,000 gallons.
Why we like it: The original Sawyer Squeeze filter revolutionized backpacking water filtration. Before the Squeeze filters were bulky, heavy, and cumbersome to use and carry. The Micro is an even smaller filter than the original Squeeze and offers all the filtration capability of filters ten times its size plus it provides a substantially longer filter lifespan. It’s the best filter to put into your bug out bag if you’re moving solo or are concerned about your group getting split up.
Flaws: The only flaw to the Micro is that it isn’t capable of filtering out viruses. If you’re based in North America this isn’t a huge issue, but if you plan to travel abroad you should look into a full water purifier.
2. Platypus GravityWorks 4.0 Liter
The Platypus GravityWorks 4.0 Liter is a gravity-fed water filter designed for use by medium to large groups. It can filter a ton of water rapidly using nothing but the force of gravity and the includes dirty/clean pouches. It’s capable of filtering 99.9999% of bacteria and 99.9% of protozoa such as cryptosporidium and giardia.
Why we like it: The two pouch gravity-fed filter system is both lightweight and extremely quick. You can filter over a gallon of water in just 2.5 minutes without putting any effort into it. The very clear markings on the bags are also a real help in telling which bag is for dirty water and which holds filtered water.
Flaws: It’s a great system, but it’s definitely overkill for one person. If you’re building out individual bug out bags for each member of the family it may be more efficient to put a single person water filter instead of a large group filter like the GravityWorks.
3. Grayl Geopress
The Grayl Geopress is an innovative water purifier bottle that uses your own bodyweight to rapidly remove bacteria, viruses, and protozoa from suspect water. Instead of relying on a pump of external squeeze pouch the Geopress uses a pair of nesting water bottles with a filter in between. By pushing it down you filter out bacteria, viruses, and protozoan cysts.
Why we like it: The compression filter system is one of the easiest to use we’ve ever seen. You end up with 24 oz of water filtered of viruses, bacteria, and protozoan cysts in just a few seconds with minimal effort. It’s perfect to bring with you on international travels where even the water in the tap is suspect and requires purification.
Flaws: The Geopress doesn’t offer anywhere close the filter lifespan of many other water filters. It’s great if you need the level of protection it provides, but if you don’t there are more affordable and longer-lasting options available.
4. LifeStraw Personal Water Filter
The LifeStraw is one of the most well-known devices in the preparedness and international aid communities. It was built to be the ultimate device to hand out en masse to people living without access to clean drinking water and functions as an individual use straw filter. It filters down to .2 microns and can remove 99.9999% of waterborne bacteria and up to 99.9% of waterborne protozoan parasites.
Why we like it: The LifeStraw is the epitome of the point and shoot mentality. If you know how to use a straw you know how to effectively use the LifeStraw. Anyone, at any age, can use the LifeStraw to get access to safe drinking water no matter what their skill level.
Flaws: The biggest limitation of the LifeStraw is that it’s a straw. It can’t filter water ahead of time and can’t be used to filter larger amounts of water for carrying. You can carry dirty water in a bottle and drink through your straw, but you then have to sanitize your bottle before filling it up at pure sources.
5. Survival Filter Pro
The Survival Filter Pro is a preparedness focused water purifier designed to remove some of the most harmful pathogens and contaminants from water. It’s an old-school pump-style filter that uses some of the most effective filter elements available in a backpacking water filter. It actually filters down to the .01 micron level, far smaller than most commercial hiking water filters.
Why we like it: The Pro can remove almost every threat from contaminated water. It offers comprehensive protection from the most obvious threats such as bacteria, viruses, and protozoa, but also pulls out mercury, lead, and other heavy metals. There aren’t a lot of backpacking water filters that can give you that level of water purification.
Flaws: As a pump filter, the Pro is bulkier and less convenient to use than squeeze or gravity style filters. It offers a great flow rate and filter lifespan, but it isn’t quite as easy to use and it takes up a lot more space in your pack.
6. Steripen Ultra UV Water Purifier
The Steripen Ultra is a UV water purifier pen designed to provide pathogen-free drinking water anywhere in the world. It’s capable of destroying 99.9% of bacteria, viruses, and protozoa in under a minute. The rechargeable battery cuts down on the total cost of ownership compared to other UV filters powered by primary batteries and has a lifespan rated at 15,000 liters.
Why we like it: Steripen has long cemented its place as the best UV filter maker in the world. The Ultra is a compact and convenient water purification device that works well for world travelers or preppers alike. It’s durable, reliable, and can effectively purify water of all the dangerous pathogens you have to worry about.
Flaws: Anything battery powered has a point of failure that non-powered devices lack. Steripen has an excellent track record for reliability, but it can be easy to forget to maintain the charge on the purifier in your bug out bag. The last thing you want is to have your family’s lives on the line and discover the battery is dead and you can’t purify water.
7. LifeStraw Flex Advanced Water Filter with Gravity Bag
The LifeStraw Flex is a larger and more group focused version of the original LifeStraw. It’s a gravity-fed water filter designed to provide water for multiple people or to work as a single person filter. It can filter out 99.999999% of bacteria, 99.999% of protozoa, and 99.999% of microplastics.
Why we like it: The Flex offers substantial filter capacity for a medium to large size group and is capable of removing the most dangerous pathogenic bacteria and protozoa. It’s designed to provide maximum flexibility in how and where it’s used and can be fitted to water bottles, the included gravity bag, pouches, and even used as a straw directly into the water source.
Flaws: The filter on the Flex, while highly capable, has a significantly reduced lifespan compared to other group water filters. It can’t effectively be back washed for cleaning and has to be replaced after just 500 gallons.
8. CrazyCap UV Water Purifier
The CrazyCap UV Water Purifier combines a compact UV purifier with a stylish double-walled vacuum water bottle. It allows you to kill every type of dangerous pathogen in minutes and has a working lifespan of tens of thousands of gallons of water. The UV light emitted by the cap does double duty as a cleaning device for the inside of the water bottle, preventing any potentially dangerous germs from building up.
Why we like it: The CrazyCap kills bacteria, viruses, and protozoa quickly and effectively. You end up with clean drinking water in just two minutes with all pathogens destroyed. The cap itself is designed to work on the included vacuum water bottle or fit onto most soda or disposable water bottles, giving you a lot of flexibility in how you use it.
Flaws: As a UV water purifier it relies on a charged battery to function. A single charge gives you up to about 35 full fills from suspect sources such as lake water but has to be recharged after that. It also can’t effectively purify murky or turbid water.
9. MSR Guardian Water Purifier
The MSR Guardian is a pump style water purifier originally designed for use at the squad level for the military. It can effectively remove viruses, bacteria, and protozoan cysts from suspect water sources and uses a unique self-cleaning design that requires almost no maintenance over its life.
Why we like it: The Guardian is a MilSpec water filter built from rugged materials with excellent filter effectiveness. It can handle the knocks and drops that come with moving rapidly across rough terrain and come out the other side ready to provide you with bacteria, virus, and protozoa free drinking water.
Flaws: One word: Price. The Guardian was built as a premium water filter and demands a premium price. You can buy multiples of most other backpacking water filters for the price of a single Guardian.
10. HydroBlu Versa Flow Water Filter
The HydroBlu Versa Flow is a low-cost squeeze style filter designed for maximum filter life and extreme portability. It weighs just two ounces yet is capable of filtering up to 100,000 gallons of water with proper care. The .1 micron filter element can remove 99.9999% of harmful bacteria and protozoan cysts such as giardia, e. Coli, and cryptosporidium.
Why we like it: The Versa Flow is compact, lightweight, and inexpensive. It’s easy to use and easier to maintain. You can pick one up for every member of the family for a steal of a deal and make sure everyone’s bug out bag has the ability to provide clean drinking water free from bacteria and protozoa.
Flaws: It’s an almost exact copy of the extremely popular Sawyer Mini, down to the attachment points and filter effectiveness. It’s slightly cheaper, which is nice, but it doesn’t have the same track record for quality.
What’s new with backpacking water filters
Who should buy a backpacking water filter?
A water filter is honestly one of the things a prepper should acquire very early in their preparedness journey. Water is life, and having the ability to filter safe drinking water from uncertain sources can save you and your family in a huge variety of emergencies. That being said, the groups below can benefit right now from a quality backpacking water filter.
Hikers, backpackers, and campers – It’s an obvious point to make, but hikers and backpackers are some of the people who can most benefit from a backpacking filter. They’re frequently out doing strenuous activities where supplies of clean water are scarce.
A quality water filter allows you to carry less water at the start of your journey and provides clean drinking, cooking, and cleaning water as needed. You can refill your water bottles and hydration reservoirs as you come across water sources no matter how dirty they seem to be.
Preppers building a bug out bag – If you’re putting together a bug out bag you should absolutely include a water filter. Water is second only to warmth in importance when talking about survival needs.
The ability to provide clean drinking water to your family while bugging out can be the difference between life and death. What type of filter to include depends on the size and age range of your group. If you’ve got a lot of younger kids with you it may make more sense to go for a few larger water filters that can serve more people.
If it’s mostly adults and older teens individual filters give you much more flexibility and ensure everyone has access to clean water even if they get separated.
Backcountry workers – If your job takes you out into the backcountry it’s a very good idea to carry a water filter. This includes everyone from recreational hiking and rafting guides to forest rangers, logging workers, and similar extraction industry professionals.
Given how light they are now, some high-quality water filters weight just a few ounces, there’s no reason not to throw one into your rucksack or keep it in a spare pocket. Having the ability to filter water if you end up in a survival scenario can be a major game-changer.
World travelers – If you’re traveling to new places around the world for work or pleasure, a lightweight backpacking water filter is a really good addition to your bag. Much of the developing world has inadequate water purification and treatment facilities (1).
The best thing to do is only drink sealed bottled water, but carrying a water filter is a good backup plan. It allows you to remove the bulk of dangerous pathogens that can seriously sicken you while traveling.
How we ranked
We used five comparison points to put together our list. These were filter/purifier effectiveness, ease of use, portability, flow rate/filter lifespan, and required maintenance.
Filter/Purifier effectiveness – For any water filter or purifier, its effectiveness is the absolute most important factor to consider. It doesn’t matter how portable or convenient to use it is if a filter can’t actually get the job done.
We considered manufacturer claims about filter effectiveness, including what pathogens it can remove, and how they backed up their claims. The main body to look to for backpacking filter effectiveness is the National Sanitation Foundation (NSF). They provide independent lab testing of water filters and purifiers to determine how effective they actually are (2).
If a filter lacks NSF certification we didn’t consider it for our list.
Ease of use – How a filter works and how easy it is to use was our second most important consideration. Old-school pump filters really can’t compare to new techniques such as squeeze style filters or high-flow gravity filters.
When comparing different models we looked at how easy it was to set them up, fill the dirty water reservoir, move water through the filter element, and use/store the clean water. We also looked at things like labeling of dirty/clean reservoirs and ease of packing away.
Portability – Portability is essential for an effective backpacking water filter. The best filters are compact, lightweight, and easy to fit into a backpack or bug out bag. They should also include as few separate parts to misplace as possible.
We gave some leeway depending on how many people a specific filter was designed to serve. A single person filter is obviously smaller and lighter than one designed for a group of four.
Flow rate/filter lifespan – The flow rate of a filter is the biggest determining factor for how many people it can effectively serve. Filters with higher flow rate can be used for larger groups, though they’re also usually more expensive.
One thing to double-check with the flow rate is how it affects filter effectiveness. Some cheaper filters increase the flow rate by lowering overall filter effectiveness. This is a big no-no.
Lifespan is the biggest factor that will determine the overall cost of ownership for your filter. Filters with higher lifespans are always better, though they may also be more expensive.
Required maintenance – Any backpacking filter is going to require regular maintenance to work at its best. For the best filters, this is a matter of backflushing the filter element and cleaning out the squeeze pouches or reservoir bags.
We looked for filters that provided the most effective service with the least onerous maintenance requirements.
Brands we trust – Two brands that really stand out in the water filter space as Sawyer Products and Platypus. They both originated in the world of ultralight hiking and offer excellent filters that weigh almost nothing, yet offer tens of thousands of gallons of filtered water. Both companies have a range of different filter options from single person miniature filters all the way up to expedition ready gravity filters for large groups.
Things to avoid – The biggest mistake we see preppers making with water treatment options is preparing for the wrong threat environment. If you’re located in North America you can get by no problem with a basic water filter capable of removing bacteria and protozoan cysts. For those located elsewhere, and especially those prepping in the developing world, you need a full up water purifier capable of removing viruses as well.
We ranked each of these factors in order of importance and compared how the filters under consideration fared. The ones on our list were the top of the heap for their respective filter type and use.
Backpacking water filters are incredibly portable and easy to use – Until relatively recently backpacking water filters were bulky, heavy affairs that you had to pump or use another active pressure system to use. Nowadays the best backpacking water filters weigh just a few ounces and rely on easy to use squeeze pouches or even the force of gravity to filter your water.
You can get a filter capable of purifying thousands of liters of water that will fit in your pocket. Even better, the new generation of ultralight and highly effective filters are more affordable than the ones that came before them.
Backpacking water filters give you safe water wherever you find yourself – The beauty of ultralight backpacking filters is that they’re easy to take with you everywhere you go. You can fit a highly effective water filter in your pocket and filter water anywhere on Earth.
If you’re based in North America it’s even easier as you don’t usually need to worry about viruses in your water. For those who find themselves in parts of the developing world, they make specialized purifiers rated to remove both pathogenic bacteria and viruses. These will keep you and your family safe no matter where you end up (3).
Backpacking water filters are extremely affordable – Modern backpacking water filters have never been more affordable. Up until just a few years ago any water filter that could actually do a good job cost a lot of money. We’re talking up to and above $100 for a filter that was ten times the weight and five times the size.
Thankfully you can now get water filters that are smaller, lighter, and more effective for a fraction of the price. They’ve gotten cheap enough it’s completely doable for any serious prepper to pick up enough filters to keep one in every bug out bag, vehicle, and storage cache they have.
Backpacking water filters fulfill one of the most basic needs of human survival – In the hierarchy of survival needs, dehydration ranks just below exposure as the fastest killer. Your average person can only go hours without water before noticing physical and mental impairment and can die within days (4).
Just having water itself isn’t enough though, as even the clearest and purest mountain streams are filled with millions and millions of microorganisms. Lack of water will kill you within days, but drinking contaminated water can kill you just as quickly through the water you lose from gastrointestinal bugs like cryptosporidium, e.coli, and giardia (5).
A modern backpacking filter can remove up to 99.9999% of these deadly pathogens, giving you and your family a clean source of water in even the most remote areas.
Backpacking water filters last a shockingly long time – If you’ve been hiking and camping for a long time you no doubt remember the annoyance of replacing backpacking filters. Some of the older models might only provide you with a hundred or so gallons before you had to get a new filter element.
Modern backpacking filters are substantially longer lasting than those old-school filters. The best models can provide tens of thousands of gallons of water, while even value-priced ones will give you at least several hundred to several thousand depending on conditions (6).
Q: Do I need a backpacking water filter?
A: Absolutely. Even the cleanest and fastest flowing mountain stream water is host to millions and millions of tiny pathogenic bacteria. In North America the biggest threats are bacteria like e. Coli, salmonella, and shigella, plus protozoan cysts such as cryptosporidium and Giardia.
These can cause severe gastrointestinal distress that can lead to serious dehydration. In a survival situation polluted water can be lethal if not properly filtered (7).
Q: How long do backpacking water filters last?
A: This varies a lot depending on the filter in question. The best modern backpacking filters will probably outlast your need for them. Many filters priced under $50 can filter tens of thousands of gallons of water when properly maintained. That’s more water than most preppers will ever need while out in the wilds.
Q: When should I replace my backpacking water filter?
A: Most manufacturers will include an estimated filter lifespan on their product. If you’re unsure how much water you’ve put through yours a good rule of thumb is to replace it when cleaning no longer improves water flow. Modern filters use membranes with tiny holes that prevent bacteria and other pathogens from passing through. Eventually these will clog up to the point where you can no longer clear them out.
Q: How do I clean a backpacking water filter?
A: The exact cleaning methods will vary from filter to filter but there are a few basic methods that you can follow to maximize the lifespan of most filters. While using your filter do your best to draw from the clearest source of water possible. You should also periodically backwash your filter with pure water to push any particulates out of the filter membrane. Once you’re back home you should flush your filter out with a dilute solution of bleach. This helps prevent bacteria from growing in the filter itself (8).
Q: How safe are backpacking water filters?
A: Very safe. Modern backpacking filters are capable of removing the vast majority of pathogenic bacteria and protozoan cysts, the things you most need to look out for in North America. If you’re traveling in the developing world or other places with viral contaminants you need a water purifier. There are several great examples of both on our list.
Q: What’s the difference between a water filter and a water purifier?
A: There are a lot of technical differences specific to different filters and purifiers, but the simple answer is that water purifiers remove viruses and water filters don’t. Viruses are much, much smaller than bacteria or protozoan cysts. A quality water purifier is needed if you’re prepping in an area with viral contamination in your water (9) (10).
Q: What’s the most portable backpacking water filter?
A: One of the great things about modern material sciences is the tremendous increase in miniaturization in hiking and preparedness gear. Modern backpacking filters can be as small as a few inches long and weigh just a few ounces while offering performance superior to much, much larger models.
Our pick for the most portable backpacking water filter, also our overall top pick, is the Sawyer Products Micro.
Q: What’s the best backpacking water filter for a group?
A: A group of people needs a lot more water than a single person does. If you’re planning to bug out with your family it doesn’t always make sense for everyone to have a small single-person water filter, especially if you have small children. A group water filter allows one member of your group to rapidly filter enough water for everyone to use.
Our pick for best group backpacking water filter is the Platypus GravityWorks 4.0 Liter.
Q: What’s the best gravity backpacking water filter?
A: Gravity-fed backpacking water filters offer substantial benefits over squeeze or pump models. They can rapidly filter a lot of water without you having to do much of anything. If you’re moving with a group a gravity-fed water filter is by far the best option.
Our pick for best gravity-fed backpacking water filter is the Platypus GravityWorks 4.0 Liter.
Q: Should I use a prefilter?
A: Yes. Whenever possible you should always use a prefilter for your water. This can be as simple as putting a double thickness of a handkerchief across the opening of your dirty water bottle or bag.
Using a prefilter greatly reduces the amount of dirt and other large particles that your filter has to deal with and lets it focus on removing bacteria and other microscopic threats. Consistently using a prefilter can vastly improve the lifespan of your water filter.
Q: Do backpacking water filters remove viruses?
A: No. If you need to remove viruses from your water supply you need a water purifier. Backpacking water purifiers are capable of removing viruses alongside bacteria and protozoan cysts. These use much smaller filter membranes that can block even tiny viruses.
One thing to keep in mind though is that water purifiers don’t have the same lifespan as many filters. The tiny homes they use to filter out viruses clog up much more easily than the larger ones of filters.
Our top pick for a water purifier is the Grayl Geopress.
Q: How do UV water filters work?
A: UV water filters are a marvel of modern technology. Instead of relying on a physical filter powerful Ultraviolet light is used to destroy the DNA inside pathogens. UV filters can effectively kill bacteria, protozoan cysts, and viruses without adding any kind of chemical taste to your water. The only real downside to UV water filters is that they don’t remove any physical particles within your water. UV filters also won’t work if the water is especially cloudy (11).
Backpacking water filters are some of the lightest yet most effective water treatment options out there. The best models weigh just a few ounces yet are capable of providing tens of thousands of gallons of pure water for you and your family.
You should absolutely include a water filter in every bug out bag you put together. Protecting your family from the dangers of germ-infested water will pay off the tiny investment many times over.
For Survival At Home’s #1 backpacking water filter recommendation, click here.
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