If you’re planning a multi-day hiking trip or remote camping expedition, water is a huge concern. Water takes up a ton of space and is heavy to carry around so most people cannot possibly bring all the H2O they need for a long trip. Thankfully, there are backcountry water filtration and purification systems designed to take river or lake water and make it safe to drink. All filtration systems remove bacteria and protozoans that’ll make you sick. Some systems will even remove viruses, pesticides and other nastiness from the water. We’ve tested a wide variety of these filtration systems and chose the best of the best for your backpacking and camping needs. If you need to purify your home water, we cover home filters are over here.
MSR Trail Base 2L
The best overall filtration system
Why should you buy this: The MSR Trail Base is one of the most versatile filtration systems on the market, allowing you to use it whole as a gravity system or break it apart into a pocket-sized filter and a portable 2L reservoir.
Who’s it for: Campers and backpackers in a group who want to purify two liters of water or more at a time.
How much will it cost: $139
Why we picked the MSR Trail Base:
This MSR Trail Base 2L filtration system uses two bags — one for dirty water and one for clean water. The bags work as you would expect — you pour the unfiltered water into the “dirty” bag and use gravity to filter into the clean bag. This dual-bag system minimizes any contamination and helps to keep your clean water clean. It also filters exceptionally fast. The Trail Base hollow fiber filters remove bacteria and protozoans, but not viruses. It cleans easily as well — just shake or swish to remove any debris.
What sets the Trail Base apart from the competing gravity filters by Platypus and Katadyn is the modular design of the Trail Base. You can use the whole kit as a basecamp gravity filtration system or break it apart and use the filter and reservoirs individually. The pocket-sized trail shot filter is outstanding. It has a short hose that allows you to reach even the smallest puddle of water and filters water quickly using a small hand pump. It’s fast — we were able to fill a 1-liter SmartWater bottle in under a minute.
The Trail Base is available now with a 2L reservoir. If 2L is not big enough, then just wait a little longer. MSR is preparing to release a 4L Trail Base version and a 10L AutoFlowXL Gravity Filter system in February 2019.
Sawyer Squeeze Water Filter System
The best ultralight water filtration system
Why should you buy this: The Sawyer Squeeze strikes an excellent balance — it’s not too big, not too expensive and is effective at filtering disease-causing bacteria and protozoa.
Who’s it for: Backpackers who want a light, yet effective water filter.
How much will it cost: $40
Why we picked the Sawyer Squeeze:
The Squeeze gets its name from the included pouch: Fill the bag up at a nearby stream, attach the filter head, and squeeze the purified water into a container or bucket of your choice for fresh water. It filters bacteria and protozoans, but not viruses. The pouch collapses easily for great storage when you aren’t using it, making this option particularly backpack friendly.
However, the filter is an adaptable little guy — it has attachments that allow you to fit it over a faucet for purified water during emergencies (or doubtful water quality), or you can use the included bucket adapter to fill a bucket for showers and other more substantial needs. According to Sawyer, the filter gets rid of 99.99999 percent of bacteria and protozoa. It’s a particularly versatile purifier for just $40, making it an excellent option if you aren’t sure what to get.
Sawyer also makes the currently available Sawyer mini and the upcoming micro squeeze. The mini is a smaller version of the squeeze that is equally easy to use and as efficient as its bigger brother. Available in fall 2018, the micro squeeze is petite like the mini but with a faster flow rate that rivals the full-sized Squeeze.
MSR Guardian Purifier
The best for International travel
Why should you buy this: The MSR Guardian is a powerhouse of a purifier that can remove particulates, bacteria, and viruses at a rate of 2.5 liters per minute.
Who’s it for: Backpackers and international travelers who want a bullet-proof water filtration system.
How much will it cost: $349
Why we picked the MSR Guardian:
When you need clean water no matter what, the MSR Guardian is the purification system for you It is a military-certified pump that handles both bacteria and viruses with ease, pumping up to 2.5 liters per minute with a reliable water source at hand (and someone who won’t get tired of pumping). The pump is self-cleaning and lasts for more than 10,000 liters before the filter cartridge needs replacing. It also withstands freezing temperatures and other harsh conditions. If you want to put the “base” in basecamp, this is the water purifier for you. Of course, you’ll have to find a way to lug the thing around with you.
Aquamira Water Treatment Drops
The best chemical purification
Why should you buy this: Aquamira water treatment drops are a great alternative when you don’t want to carry a filter or have a filter that fails.
Who’s it for: Backpackers who want a cheap and easy way to sterilize water without having to carry a filter.
How much will it cost: $15
Why we picked the Aquamira water treatment drops:
The traditional water sterilizer used to consist of tablets or liquid you put into water to help kill bacteria and make it safe to drink. These chemical treatments aren’t as convenient as filter-based water purifiers, which is why they’ve mostly been replaced on the market. They are still a useful alternative for a couple reasons: they’re cheap, very effective and they don’t take up much room in your pack. Aquamira is our top pick because it uses chlorine dioxide, which kills everything (bacteria, protozoans, and viruses) in the water and doesn’t change the taste or the color of the water.
You can buy 1 ounce of Aquamira for $15 and store it for an emergency. Because it uses two separate solutions that are inert, the treatment has an extraordinarily long shelf life of four years, even after you open it. The liquid form also is fast-acting when compared to the tablets. You don’t have to deal with tablets that sometimes are difficult to dissolve and take up to four hours to work. As soon as the Aquamira liquid is activated, the chemicals get right to work on the nasties in your water.
Using Aquamira is a two-step process. You first mix solution A with solution B according to manufacturer’s directions and wait 8 minutes for the chemicals to react and form chlorine dioxide. You then add the chemical mixture to your bottle or bladder and wait for 30-minutes while the dangerous microorganisms (bacteria, virus, protozoa) are killed off. During this process, the chlorine dioxide is neutralized so they don’t leave a bad aftertaste like iodine does. It takes some planning to get potable water when you are using with Aquamira, but you don’t have to deal with clogged filters or dead UV pens that fail when you need them the most.
Platypus GravityWorks 4L
The best gravity filtration system
Why should you buy this: The Platypus GravityWorks
Who’s it for: People who don’t like pumping
How much will it cost: $119
Why we picked the Platypus GravityWorks 4L:
This 4L filtration system has an interesting dual-bag set-up. Pour water into one bag and it empties into another as it filters, allowing you to control how much water is filtered at one time. Unfortunately, it doesn’t filter water that’s potentially contaminated with viruses but it remains a very strong option for a basecamp that needs a reliable source of potable water. The filtration speed is particularly fast, which is nice if you go through a lot of water while cooking or cleaning. It filters bacteria and protozoans, but not viruses.
Katadyn BeFree 0.6L
The best bottle filtration system
Why should you buy this: The Katadyn BeFree water bottle and filter combo is so lightweight that you’ll forget it is in your pack.
Who’s it for: Backpackers and trail runners who want a water bottle they can fill and then filter on the go.
How much will it cost: $39
Why we picked the Katadyn BeFree 0.6L:
The Katadyn BeFree water bottle is a simple yet efficient filter for hikers and trail runners who don’t want to invest a lot of time or effort into treating water. The soft-sided flask fills quickly in a water source thanks to the wide 42mm opening. You simply fill the flask, screw on the filter and drink as you go. The fast-flowing treatment system lets you filter two liters per minute and can be cleaned with a shake or a swish. It filters bacteria and protozoans, but not viruses.
The flask portion of the system is its weak point. You have to treat it gently or it may develop a leak. The flask is made by Hydrapak, which sells a variety of soft-sided water bottles. You can use the BeFree filter with any of Hydrapak’s products that have a 42mm opening including the handheld Softflask 500ml and the collapsible Seeker – Collapsible water storage bag.
Steripen Ultra UV Water Purifier
The best cold weather purification system
Why should you buy this: The Steripen Ultra UV Water Purifier kills bacteria, protozoans, and viruses in a literal minute.
Who’s it for: Backpackers who want a purification system that works in all temperatures and all conditions.
How much will it cost: $109
Why we picked the Steripen Ultra UV Water Purifier:
When temperatures plunge below freezing in the shoulder season, water filtration gets a bit more complicated. Filtration systems may freeze and develop cracks that compromise the system. Chemical treatments don’t perform well either as the lower temperatures slow down the reaction time. You can boil your water but that requires you to bring extra fuel. The best cold weather option is the Steripen, a battery-powered UV filter system.
To use the Steripen, you simply place the probe into your water source, turn on the device and stir for approximately 90 seconds (or until the unit tells you that the purification is complete). The UV light disrupts the DNA of viruses, bacteria, and protozoans during the purification process. Each light is capable of up to 8,000 treatments over its lifetime. If you exceed this limit, Steripen will replace the light for free.
Because the Steripen uses batteries, you have to keep an eye on your battery level to make sure you have enough juice to purify your water. The Ultra model we selected has a rechargeable battery that you can plug into any charging block or wall plug using the supplied USB cable. Each full charge can purify up to 50 liters of water. The unit conveniently has an onboard battery meter so you know precisely how much charge you have left. Steripen also sells units that are powered by AA-batteries if you don’t carry a charger and prefer to use standard batteries.
The best budget water filtration system
Why should you buy this: The Lifestraw retails for $20 and is often on sale, making it a no-brainer filter to always have in your pack for the SHTF moments.
Who’s it for: Backpackers or travelers who want an easy-to-pack filter that you can use like a straw to sip from a lake or stream.
How much will it cost: $19
Why we picked the Lifestraw:
Just dip and sip. That is how easy it is to use a Lifestraw. As its name implies, the Lifestraw is a straw with a filter built inside of it. It filters bacteria and protozoans, but not viruses and can filter 4,000 liters (1,000 gallons) of water over its lifetime. You place one end in the water source and use the mouthpiece end to suck up the water. It takes a few minutes of sucking to get a good flow, but once it is working you can get a mouthful of water with each suck. The Lifestraws are prone to clogging so be careful not to such up too much sediment and take the time to backwash after each use. This regular maintenance will ensure you get years of use out of the straw.
Things to Consider
Do You Need a Filter or a Purifier?
Keep in mind that when people talk about backcountry water treatment, they mean, “Make natural water drinkable,” and that’s the definition we used here. There are actually two types of water treatment — water filters and water purifiers. The primary difference between the two is the size of the organisms that they remove from the water.
Filters are popular among hikers and backpackers because they are relatively cheap, packable and easy to use. They use a hollow fiber membrane or similar material with microscopic pores. These pores are small enough that they will remove bacteria and protozoans (such as Cryptosporidium and Giardia lamblia) found in mountain rivers, lakes, and similar bodies of water. Filters are convenient, but they require some maintenance. They can get clogged with debris, especially if you don’t pre-filter the water to remove sediment and organic material. To unclog a filter, you need to backwash it periodically according to the manufacturer’s directions.
True purifiers (which are also on our list) tend to use specialized filters, UV light or chemical options to kill viruses in addition to bacteria and protozoans. Viruses often aren’t a significant concern when traveling to remote streams or lakes, but in undeveloped countries, or in rivers where people tend to congregate, virus-killing purification is necessary. Don’t go unprepared or even underprepared when it comes to treating your water in any unsanitary locations.
Besides making water safe to drink, some filters and purifiers also include activated charcoal in the filtration system because it helps to remove unpleasant tastes from the water. It also is effective at removing heavy metals, pesticides, and other industrial/agricultural by-products.
Do I need a Backup?
Absolutely, yes! You should carry a backup water treatment when you are going into the woods for more than a few hours. No water treatment is foolproof. We’ve had our filter clog unexpectedly on the trail, accidentally left it outside to freeze and even forgotten to pack it. Having a backup in these circumstances allowed us to continue on our trip and not have to turn back because we couldn’t treat our water. If you travel in a group, you can share the load. As long as two people have a water treatment option, you shouldn’t have any problems with water. If you have no water filters or purifiers and you absolutely need water, you also can boil it for 10 minutes before using it to drink or eat. Boiling is as effective as any of the filters or purifiers, it just takes time and patience.
Storage and Care
Treat your water treatments systems with some TLC and they will last you for years. Abuse them and you may end up pooping your pants and puking your guts out from some nasty intestinal bug. During your hike, you need to watch out for two things — any particulate matter that’ll clog your filter or below freezing temperatures that’ll freeze your filters. Preventing particulate is simple — choose a cleaner water source if possible or use a cloth as a pre-filter to remove the sediments and silt. Freezing your filter is a bigger issue during the shoulder season but it can easily be avoided by sleeping with the filter in your sleeping bag.
When you are done hiking or backpacking, you should backwash your filter to remove any debris if recommended by the manufacturer and then sanitize it. You can sanitize it using chlorine dioxide drops or diluted bleach and allow it thoroughly dry before storing.