During a big backpacking trip, water is one of the heaviest things you can carry in your pack. Thankfully, you often don’t have to carry much – nature is filled with water so you can replenish your water bottles as you hike.
However, it’s important to keep in mind that most water you find in the wild isn’t safe for drinking without treatment. Disease-causing bacteria and viruses are common in the water sources you’ll encounter while backpacking, even if they look clear and pristine.
That’s why bringing a reliable backpacking water filter on every trip is extremely important. Backpacking water filters are specifically designed to be lightweight and easy to use in the backcountry, while removing dangerous pathogens from nearly any water source. With a backpacking water filter on hand, you can quickly and safely quench your thirst from any creek or lake you encounter on your route.
Today, we’ll take a look at how to choose the best water filter for backpacking, as well as review eight of the best backpacking water filters on the market today.
How to Choose the Best Backpacking Water Filter
There are a huge variety of water filters on the market, which can make it hard to figure out which one is best suited for your backpacking trips. That said, understanding the differences between water filters and how they work can allow you to identify which filter will work best for you.
- Water Filters vs. Water Purifiers
When it comes to filtering dangerous pathogens out of water sources, not all filters are created equally.
So-called water filters use a very tiny mesh or ceramic filter that physically strains out bacteria and disease-causing protozoa like Giardia. However, viruses are too small for these filters and will pass through into your water. If you’re travelling in North America, this isn’t a huge problem – disease-causing viruses are relatively rare in backcountry water sources.
Water purifiers, on the other hand, use chemical treatment or UV irradiation to kill bacteria, protozoa, and viruses. While this broader range of treatment can be handy, chemical treatment often leaves a bad taste in the water and UV light is effective only for treating water in small volumes.
- Pump Filters
Pump filters are the kind of water filter you’ll see used most frequently on expedition-style backpacking trips. These usually involve a manual pump that allows you to suck water from a creek or lake, through a filter, and into a collection bottle. Pump filters can be somewhat heavy and require regular maintenance, but they are extremely reliable and good for filtering large volumes of water. Plus, pump purifiers are also available.
- Gravity Filters
Gravity filters are much like pump filters, except that you are relying on gravity to help push the water through the filter so that there’s no need for manual pumping. Gravity filtration can be slow, but the low level of work involved makes it ideal for filtering very large volumes of water for multiple people when sitting around camp.
- Bottle Filters
Bottle filters allow you to treat water either in your water bottle or as you drink from it. Some bottle filters have a standard filter that uses the force of you sucking on the bottle to draw water through it. While these systems are often fast and light, keep in mind that the amount of water you can treat on the go is limited to the volume of the bottle.
- Squeeze Filters
For many solo backpackers, squeeze filters represent the perfect medium between bottle filters and pump filters. With a squeeze filter, you fill a dedicated reservoir bag with untreated water, then squeeze it through a filter into your water bottle. These filters are extremely small and lightweight, fast to use, and you’re not limited in the amount of water volume you can treat.
- Straw Filters
Straw filters are popular one-person water treatment solutions that allow you to drink water directly from a creek or lake. Similar to a bottle filter, you use your mouth to suck water through the filter. While straw filters can save weight for a light and fast trip, they’re less than ideal because you have to get your head down to within a few inches of your water source and they don’t allow you to filter water into a bottle to carry with you.
- UV Purifiers
Pen-style UV purifiers are designed to be dipped into your water bottle and stirred around for about 60 seconds – after that, your water is completely free of all pathogens including viruses. These purifiers are extremely lightweight and simple to use, but they will only treat a small volume at one time and run on batteries. In addition, the effectiveness of UV prefilters is questionable in cloudy or silty water, so you’ll need to prefilter your water.
- Do You Need a Prefilter?
Depending on what your water source looks like, you may need to prefilter your water before running it through your backpacking filter or purifying it. A prefilter is simply a fine mesh filter that helps to remove silt and other particles, which in turn helps prevents your main filter from becoming clogged. If your water purification system relies on UV, you should absolutely use a prefilter since UV light cannot penetrate through these particles.
Many pump filters come with prefilters, and it’s easy to add a prefilter to most other types of filters.
The 8 Best Backpacking Water Filters of 2019 – Compared & Tested
1. Lifestraw Personal Water Filter – Best for Light and Fast Backpacking
This inexpensive straw filter from Lifestraw allows you to drink straight from virtually any water source without carrying a water bottle. At only two ounces, it is one of the lightest water filtration devices available for backpacking and rivals even iodine tablets in weight. That makes the Lifestraw water filter ideal for light and fast backpacking trips, particularly in areas where water is plentiful.
The straw uses a microfiltration membrane that removes bacteria and protozoa, as well as most microplastics down to one micron in size. The filter rarely experiences issues with clogging, even when sucking up silty water, and is rated to last for up to 4,000 gallons of filtration.
The downside to the Lifestraw filter is that it’s difficult to use for drinking the volume of water you need to stay hydrated on most backpacking trips. Sucking water through the straw filter requires a lot of suction, which can make your jaw ache after just a few hundred milliliters. If you’re not hiking alongside a creek or camped immediately next to a water source, it can be hard to carry water since this filter is not compatible with a water bottle. Plus, it’s easy to lose the straw into a creek if you drop it from your mouth.
- Weighs just two ounces
- Rarely clogs
- Filters out microplastics
- Lasts up to 4,000 gallons
- Requires a lot of jaw action to suck on
- Doesn’t work with a water bottle
- Easily lost into a river or creek
2. Sawyer Products Mini Water Filtration System – Best Squeeze Filter
This tiny, two-ounce filter from Sawyer Products offers an intriguing hybrid between a squeeze filter and a straw filter. On the one hand, the filter comes with a 0.5-liter water reservoir that can be filled up with untreated water and then rolled upwards to force water through the filter and into a water bottle. On the other hand, the filter can be used in the style of a straw filter by screwing it onto the mouth of most disposable water bottles or dipping it directly into a water source. The filter can even be used in-line with the hose of a hydration pack, although this requires buying an integrated hose separately from the filter.
The filter is not rated for a total number of gallons it will filter, since Sawyer rates it for beyond the amount that most backpackers will ever drink. However, the filter does need to be backwashed with clean tap water at home after every trip to avoid growing mold. The filter is tight enough that it can struggle with silt – if you’ll need to filter more than ten liters of silty water, Sawyer recommends backwashing the filter in the field.
Unfortunately, in spite of the lightweight and crafty design of this filter, Sawyer does face some problems with quality control. Many units of this filter develop cracks within the first few uses, and the screw-on input often doesn’t screw cleanly onto water bottles as it is supposed to.
- Weighs just two ounces
- Comes with squeezable 0.5-liter reservoir
- Can be used as a straw filter and screwed onto standard water bottles
- Filter lasts for a lifetime of use if maintained
- Issues with quality control on filter units
- Requires backwashing after every trip
- Can clog with silty water
3. Etekcity Water Filter Straw – Best Emergency Water Filter
This straw style filter from Etekcity is perfect for ultra-light backpacking and as a backup to a larger pump or gravity filter. The filter uses a three-stage system, including a prefilter to remove large particles from silty water, an activated carbon filter to remove bacteria, and a 0.01-micron filter to remove protozoa and any remaining contaminants from your water.
The straw filter comes with a small reservoir pouch, which can allow it to be used like a squeeze filter. Plus, an integrated cap keeps the drinking nozzle safe from contaminated water as you’re approaching your water source. The filter also comes with a syringe for backflushing it before and after your trip to keep it in prime condition.
Like the Lifestraw straw filter, this filter can be difficult to suck water through – which makes it best as an emergency backup rather than your primary filtration system. In addition, while the prefilter helps to prevent clogging, the prefilter itself can quickly become clogged and it’s easy to clog all of the included prefilters over the course of a multiday trip.
Finally, while the Etekcity filter has a lot in common with the Lifestraw, it has a lifespan of only 1,500 liters compared to the 4,000-liter lifespan of the Lifestraw filter.
- Three-stage filtration system
- Includes multiple prefilter attachments
- Comes with reservoir pouch for use as squeeze filter
- Difficult to suck water through the filter
- Prefilters can clog quickly
- Lifespan of filter is limited to 1,500 liters
4. Platypus GravityWorks 4-liter Water Filter System – Best Filtration System for Groups
This high-capacity gravity filtration system from Platypus is the perfect companion for backpacking with a larger group. The system is comprised of two four-liter reservoirs with a hose and an in-line filter in between them. Straps on the reservoirs make it easy to hang one on a high branch in a tree and another on a lower branch to facilitate flow through the filter between them. If you’d rather bring just one reservoir and filter directly into a standard water bottle, Platypus provides adapters for doing so.
Despite the massive four-liter reservoir capacity, the entire filtration system weighs just 11.5 ounces. Plus, it can filter water at up to 1.75 liters per minute – although expect one liter per minute or less if the water has any silt in it. Best of all, the two reservoirs allow you to carry up to eight liters of water – four untreated and four treated – if your camp is far from a water source.
The GravityWorks filter cartridge is rated to filter up to 1,500 liters in its lifetime, and can be inexpensively replaced every few years without replacing the entire filtration system. The filter can even be backwashed easily in the field by switching the positions of the clean and dirty reservoirs and squeezing the clean reservoir.
The only real downside to this system is that it’s somewhat heavy for a single person or a pair of backpackers.
- Four-liter gravity system requires no manual work
- Fast filtration is perfect for large groups
- GravityWorks filter can be easily backwashed and replaced
- Adapters to filter directly into water bottle included
- Heavy for one or two backpackers
5. Katadyn Water Filter – Most Durable Backpacking Water Filter
This pump filter from Katadyn is a tried-and-true favorite among serious backpackers. It’s simple to set up, fast to filter, and reliable in nearly any situation.
The filter works using two hoses: one that contains an inlet valve with a built-in prefilter to keep large particles away from the main filter, and one that outputs clean water directly into your water bottle. With the inlet submerged in a water source, you can pump water at up to one liter per minute – meaning you won’t waste valuable daylight waiting around for gravity filtration. Pumping does take some arm strength, but it’s well within the capabilities of any backpacker.
Incredibly, the Katadyn filter is made to handle up to 50,000 gallons of water over its lifespan. That makes its high price tag much more digestible, given that you’d need 30 units or more of most other filters to match that longevity. On top of that, the casing of the filter is metallic so that you can be sure this filter won’t break in your pack. Katadyn is so sure of this filter that it comes with a 20-year warranty – something you won’t find on any other backpacking water filter.
The biggest downside to this filter – aside from the high upfront cost – is that it weighs in at 20 ounces. That makes it one of the heaviest options for personal water filtration.
- Inlet hose has built-in prefilter
- Rated for up to 50,000 liters of filtration
- 20-year warranty
- Durable metallic casing
- Expensive up front (but cheaper long-term than other filters)
- Weighs 20 ounces
6. MSR TrailShot Filter – Best Compact Water Filter
The TrailShot filter from MSR is one of the newest backpacking water filters on the market and it’s making big waves for its ultralight weight and fast filtering. The filter operates like a hybrid between a straw and pump filter – you’ll squeeze the pump head to force water through the filter, but the short hose means you’ll need to get as close to your water source as you would with a straw filter. The spout is designed either for drinking straight from the filter or for dispensing clean water into a bottle.
The filter and pump mechanism are surprisingly fast, filtering up to one liter per minute. Even more impressive, the entire filter system weighs in at just under five ounces and is small enough to throw in your pocket while hiking.
The filter cartridge itself is rated to last up to 2,000 liters. Although replacement cartridges are available, it costs only marginally more to replace the entire filter. While the system is much more convenient than most straw filters and doesn’t require any mouth suction, it is significantly more expensive over time compared to a true pump filter like the Katadyn filter.
- Weighs less than five ounces
- Small enough to fit in a pocket
- Pump eliminates need for mouth suction
- Filters up to one liter per minute
- Somewhat short lifespan, replacement cartridges are expensive
- Hose is relatively short
7. Survivor Filter PRO – Best Water Filter for Viruses
This impressive do-it-all pump filter from Survivor Filter is capable of eliminating viruses and chemicals from your water in addition to bacteria and protozoa. The trick is a three-stage filtration system: a pre-filter removes large contaminants to prevent clogs, an activated charcoal filter eliminates bacteria and absorbs chemicals like lead and mercury, and a 0.01-micron Ultra filter catches protozoa and viruses. The activated charcoal filter also improves the taste of filtered water, increasing the range of water sources you can drink from comfortably.
Unlike similar three-stage filtration systems, the Survivor filter doesn’t suffer from clogs at the pre-filter stage. That allows the filter to run reliably close to its maximum 0.5 liter per minute flow rate. Better yet, with proper maintenance and backflushing after each trip, the filter is rated to last an incredible 100,000 liters and Survivor Filter offers a lifetime warranty.
Compared to similar water filters with that longevity, the Survivor Filter is surprisingly inexpensive. The 12.8-ounce weight is somewhat heavy for backpacking, but the speed of filtration and bomb-proof ABS shell construction more than make up for this.
- Filters out viruses and heavy metals
- 100,000-liter filter lifespan and lifetime warranty
- ABS plastic shell is highly durable
- Pre-filter is effective at preventing clogs
- Slightly heavy for backpacking, especially solo
8. RUNACC Water Filter – Best Straw Filter
RUNACC’s unique water filter adapts the straw filter design to make it significantly easier to drink from. Instead of simply offering a filter casing, RUNACC includes a hose with an in-line squeeze ball that allows you to easily force water through the filter. You can drink directly from the filter, similar to a straw filter, or use the squeeze ball to pump water into a bottle.
The ball pump is designed with one-way valves so that you never have to worry about backflow, even when squeezing in rapid succession. At its fastest, the filter can flow up to 600 milliliters of water per minute. An included prefilter, which attaches to the end of the inlet hose, ensures that you won’t have to deal with clogs.
The filter itself uses a 0.1-micron mesh that effectively captures bacteria and protozoa. While it’s only rated for filtering up to 2,000 liters, the low cost of this filter makes it easy to replace every few seasons.
It’s worth noting that the filter is significantly heavier than other straw filters – it weighs in at eight ounces. Still, the added convenience of the squeeze ball can be well worth the extra weight.
- Straw filter with in-line squeeze ball to eliminate mouth suction
- Up to 0.6 liters per minute
- Comes with clog-free prefilter
- Relatively inexpensive
- Only 2,000-liter filter lifespan
- Eight-ounce weight is somewhat heavy
Having a reliable backpacking water filter that fits your backpacking style and water needs is an essential part of every foray into the wilderness. There are many different styles of water filters available, and understanding the advantages and disadvantages of each can help you choose the right water filtration system for you. Most important, understand how to use and maintain your filter so that it works as effectively as it’s supposed to during your backpacking trips.