6 Best Water Purifiers for Fastpacking

Fastpack Water Purifiers

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Having a way to have access to natural drinking water is vital for backpackers. It allows you to drink from streams, rivers, and lakes while on multi-day hikes. 

It is even more critical for fastpackers. Fastpackers might be out just as long, but they need to travel lighter, so they will likely carry less water.  Because of the heavy amount of running when fastpacking, we need more water, but the caveat is that we can’t carry too much. The answer is water purifiers.

I discuss some of the most popular fastpacking water purifiers on the market and what I use regularly. Check it out!

6 Best Water Purifiers for Fastpacking

Drinking clean water is one of the 9 Fastpacking Rules. Catching a Giardia bug due to drinking contaminated water is no fun. We are talking about explosive diarrhea and nausea. It’s no fun, and that’s why it pays to have optimal water purification systems.

For protection against protozoa, bacteria, and even viruses, you can use one of the several fastpacking-friendly water filtration and purification devices available.


Katadyn BeFree

The Katadyn BeFree is the go-to bottle filter because of its beautiful design, portability, and ease of use.

The BeFree works with the corresponding HydraPak bottle, allowing you to drink from it like any other water bottle, with the water passing directly through the filter and into your mouth.

The lightweight, compact design of this bottle and filter system makes it excellent for long trail runs in areas with ready access to water. The wide opening makes refilling the bottle a breeze.

As a bonus, the BeFree system can be stored in the palm of your hand when empty, and the bottle’s smooth texture is a delight to hold.

The Katadyn BeFree, despite its benefits, could be better. One, it is known to clog substantially more quickly in dirty water than a filter like the “Squeeze.”

Second, the filter is only compatible with 42-millimeter apertures, making it less versatile than the Sawyer, which fits a variety of standard 28-mm water bottles.

Third, compared to the Squeeze’s gravity/inline adapter, it is more expensive by around $11 and offers fewer customization options.

However, because of its ease of use and sleek form, the BeFree excels as a bottle-specific filter, the Katadyn’s flow rate is undeniably quicker than most, the soft flask excels as a handheld, and cleaning the filter is as easy as running it in clean water.

Sawyer Squeeze

The Sawyer Squeeze filter is an excellent option since it’s easy to transport, compact, and doesn’t change the flavor of the water like certain chemical purification methods can.

It has many potential applications, but my favorite is to utilize the Sawyer Squeeze in tandem with a Smartwater Bottle to make a highly mobile and surprisingly powerful water filtration system.

Due to the inevitable degradation of Squeeze’s internal filters, a backup filter should always be packed whenever the device is taken on the trails. 

Platypus QuickDraw

The Platypus QuickDraw is a water filter that can be attached to reservoirs, 28 mm pet bottles, and platypus bottles to provide clean drinking water with just a squeeze.

You can buy a range of reservoirs and decant the water into your usual running bottles.

The QuickDraw filter is a hollow fiber filter that can process up to 3 liters per minute and, per their description, is capable of physically removing 99.9999% of bacteria, and 99.9% of protozoa.

The unit is easily maintained by just shaking or backflushing. Filter ends can be sealed to prevent water from dripping onto electronics when the device is not in use. 

water Pure

Grayl Geopress

Toxic chemicals, metals, bacteria, viruses, and even microplastics are all no match for the Grayl Geopress Water Purifier Bottle.

It takes 8 seconds for the Geopress water purifier to clean 24 ounces of dirty water, and it’s remarkably lightweight and easy to use.

This purifier is ideal for campers, fastpackers, and hikers who need to quickly filter large quantities of water and provide their companions with potable water. It can clean 5 liters of water in just one minute.

The Geopress Water Purifier’s purification cartridges are user-replaceable, and each one is good for purifying 65 gallons of water.

If your purifier breaks down on a long hiking journey, you can buy replacement cartridges for around $29.95.

MSR Guardian 

The MSR Guardian costs much more than other typical bottle filters on the list. As a water filter and purifier, in addition to a debris filter, it offers the highest possible safety against parasites, germs, and viruses.

Self-cleaning technology is employed in the Guardian, making it far less likely to break down than cheaper models.

The MSR has a ridiculously fast flow rate of 2.5 liters per minute. The result is optimal performance and confidence, whether fastpacking in densely populated areas or developing nations.

Due to its reliability and usefulness, the Guardian is used by militaries and as a disaster relief water filter.

The MSR Guardian is the best and fastest pump filter/purifier on the market, but for many individuals, it will be too much for what you need.

It’s more expensive than most filters and is noticeably heavier and thicker, coming in at a little over a pound and packing down to about the size of a 1-liter water bottle.

As you know, when fastpacking you need to try to keep your pack as light as possible…we provide some excellent tips and what to pack here, “The Ultimate Fastpacking Kit List.”

While the cleansing properties are helpful for traveling in some regions, it is unnecessary in the vast majority of wilderness areas across North America and Canada.

A necessity for some, the Guardian is the best portable purifier money can buy.

mountain safety

Chlorine Dioxide Drops and Pills

This is the other end of the spectrum when compared to the MRS Guardian, but it is something I carry in case my primary method fails.

I commonly use it as our treatment method in drop form due to its low cost, simplicity of administration, and almost hassle-free nature.

Chlorine dioxide has virtually no taste or odor and starts functioning well within a short period of time though it may take longer with drops and pills to remove some viruses.

The pills are more expensive, but they just require one tablet per liter of water to work. The drops are cheaper per liter but have a stronger flavor than the pills.

Final thoughts

Fastpackers will find the Katadyn BeFree to be the best option, but any of these filters will serve you well. This is especially true if you enjoy both fastpacking and backpacking but can only afford one filter.

One other thing I like to do when attempting longer fastpacking trips is to add salt and electrolytes to my purified water. I use Redmond Real Salt Re-Lyte powder which either comes flavored or un-flavored. Plus, our readers get 15% off their first order with this link.

I want to mention that I personally try to locate natural springs when planning my trips. I use a cool and free website called Find A Spring to see if any are close to the routes I take.

It’s still risky to drink untested spring water, so use caution and use your purification system if you believe there may be a contamination risk.

Here are 8 more actual camping tips you need to know to make your experience even better.

Either way, when out on the trails, be sure you always place water and water purity at the top of your survival list. One bad swig of water can put you in the hospital or even place you on death’s bed. We discuss more dangers in fastpacking here, or if you are newer, you will want to read The Ultimate Fastpacking Guide.

See you on the trail!

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