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Water Treatment

Need help getting started? Read our four-part guide to backcountry water treatment:
Part 1: Proper Hydration
Part 2: Keeping Your Water Supply Safe
Part 3: What’s in Backcountry Water?
Part 4: Methods for Making Water Safe

Types of Water Treatment

photo of a water purifier

Water Purifiers

photo of a pump/gravity water filter

Pump and Gravity Water Filters

photo of a bottle/inline water filter

Bottle and Inline Water Filters

photo of a chemical water treatment

Chemical Water Treatments

photo of a water filter accessory

Water Filter Accessories

Top Picks

How we choose: The best water treatment highlighted here were selected based on 640 reviews of 109 products. Our top picks are those that are readily-available in the United States and have received the highest overall ratings from reviewers.

How we test: Trailspace is powered entirely by our community of readers. The reviews posted here reflect the real-world experiences of outdoor enthusiasts just like you.

If you've used a water treatment product that you think should be listed here, please share your experience.

Disclosure: Trailspace never accepts payment for gear reviews, product placement, or editorial coverage. When you buy through affiliate links on our site, Trailspace may earn a small commission, which helps cover the costs of running the site.

Top Pump/Gravity Water Filter

Platypus GravityWorks Filter System 4L

user rating: 4.5 of 5 (20 reviews)

OMG! Seriously? If you haven't already drooled all over one of these like a lifeless zombie online or in your local shop for hours by now than you've probably already bought one. Here's why you should too. It's perfect in almost every way. Period.

Reasons to Buy

  • NO PUMPING! This is the best part. Hands down.
  • Super fast! This thing is quick. Before you get your cook pot set up it's ready to go.
  • Light. Like Feather light.
  • Small. Fits anywhere you want it to.
  • Large capacity. 4 liters at a time is plenty. Really.
  • Versatile. Rig it up with your own bladders. I don't care.
  • Easy to clean. Back wash and done.

Reasons to Avoid

  • Hmmmm. I'll get back to you on that.
  • Oh. Not 4-season. You freeze it, you broke it.

I could just list everything above in the Pros column but I have to get something in here too.  The Platypus GravityWorks Filter is a God send. It filters out everything I'm worried about accidentally ingesting plus... No more endless trips to hand pump out of the stream! No more iodine and chlorine tablets or boiling or any other negative thing any experienced backpacker can come up with when it comes to getting their potable water. It's a drag. Well, no more. Because these guys invented something called "Gravity".

Read more: Platypus GravityWorks Filter System 4L reviews (20)

Top Bottle/Inline Water Filter / Purifier

Grayl GeoPress

user rating: 5 of 5 (4 reviews)

I have been testing the Grayl GeoPress Purifier, a new, large capacity water filtration bottle, while canoeing, canoe camping, and day hiking this summer and fall. For the past three years, I have used a Grayl Ultralight Water Filter bottle, to provide clean and safe water for me and my dogs while canoeing and camping. I reviewed that bottle here on Trailspace on 10/14/18, and since then have continued to carry that bottle in my canoe bag, and occasionally, in my backpack side pockets. The new GeoPress utilizes the same fill and press filtration system as my Ultralight, but has improvements that address some of the deficiencies I found with the prior bottle. I can recommend the GeoPress for its simple operation, effective filtration performance, and increased volume. The bottle can be used by a solo paddler or hiker, but can also be used to replenish water supplies for canine or human companions.

Reasons to Buy

  • Simple operation
  • Long lasting filter
  • Durable
  • Sip top
  • Soft-press panels on lid

Reasons to Avoid

  • Tough to separate outer refill cylinder from inner cylinder
  • Requires nearly direct vertical pressure

DESCRIPTION: In the Grayl product line, the  GeoPress Purifier replaces the Grayl Quest, a similar water filtration bottle, but one which was a bit heavier, and did not have the improved features of this current GeoPress model. I am using the GeoPress as an upgrade over my Grayl Ultralight filtration bottle. The Grayl GeoPress uses a simple fill, press, and drink system to purify freshwater, but is not suitable for salt water or extremely brackish water. The filter bottle has a capacity of 24 ounces (710 ml), more than the 16-ounce capacity of the Grayl Ultralight filter bottle I have used for a few years.

Read more: Grayl GeoPress reviews (4)

Pump/Gravity Water Filter

Katadyn Pocket

user rating: 4.5 of 5 (16 reviews)

With more thought than I ever imagined, I cast my Katadyn Pocket's intake hose into the most vile, disgusting, putrescent, foulness I could possibly imagine…

Reasons to Buy

  • Filters microorganisms larger than 0.2µ
  • Silver impregnated ceramic element is effective against bacteria and protozoa
  • Filter reportedly filters up to 50,000L; 13,000gal
  • 20 year warranty period
  • Cost… Priceless!

Reasons to Avoid

  • Filter and "trail-necessary" equipment weighs 590g; 21oz
  • Carrying Case, if carried and I do, weighs 73g
  • Fairly large with dimensions of (cm): 24 x 6; (in): 10 x 2.4
  • Price… but well worth every penny!

Water: a transparent, tasteless, odorless liquid!? Hmmm, think again. I, once, with little choice, filtered water from an abandoned cow trough full of the most nauseating putrescence I've ever encountered, the only possible water source available! With more thought than I ever imagined, I cast my Katadyn Pocket intake hose into the most vile, disgusting, putrescent, foulness I could possibly imagine. A horrid faction of life defying blight (in retrospect, it may not have been that bad, but at that time…).

Read more: Katadyn Pocket reviews (16)

Top Water Purifier

MSR Guardian Purifier

user rating: 5 of 5 (5 reviews)

The MSR Guardian is a top of the line water purification system that delivers on its impressive claims. Very fast, very efficient, and largely hassle-free (requires no backflushing). Excellent for the solo hiker, but perfect for larger groups.

Reasons to Buy

  • Easy to use
  • Very fast (2-2.5L/minute)
  • No backflushing required
  • Impressive efficiency claims
  • Great for bigger groups

Reasons to Avoid

  • Initial cost may put people off
  • Getting pre-filter to engage can be annoying at times

Disclaimer: This review is purely on design, usability, durability, and my overall opinion of the product. Without access to a water testing laboratory, I cannot make any claims regarding the actual efficacy for removing harmful impurities (biological and non-biological). While I can say that I have never gotten sick drinking water filtered by the MSR Guardian, that in-itself is no validation of the claims. Without proper controls, it is merely circumstantial. Introduction: The MSR Guardian is the latest and greatest in backcountry water purification (actual wording according to MSR is "The world's most advanced backcountry purifier").  According to MSR: "Nothing is safer or easier to use for purifying the most demanding backcountry water...

Read more: MSR Guardian Purifier reviews (5)

Pump/Gravity Water Filter

Platypus GravityWorks Filter System 2L

user rating: 5 of 5 (6 reviews)

I've used the Platypus GravityWorks for about a year now. Extremely easy to use and the best part... It requires NO pumping. It's also lighter compared to some of the other water filter systems out there (especially when you ditch some of the hydration connection components that may be unnecessary based upon each individual's hydration carrying method).

Reasons to Buy

  • Lightweight
  • Easy to use

Reasons to Avoid

  • Pricey compared to pump options (Saw the Katadyn Hiker PRO at the time of this review for 60 bucks at REI)
  • The Sawyer option comes with the million gallon guarantee, while the Platypus has a filter life of 1,500 liters.

While writing this review, I am resigned to note that whatever I write, I'll probably not get anywhere close to Bill S's review, in terms of attention to detail, quality of the review, etc. etc. Actually, his review was part of the reason why I chose the GravityWorks system in the first place. But here are some of my personal experiences with the GravityWorks 2L: Effectiveness: So far, I've had nothing but good experiences with the GravityWorks. I've never gotten sick from the water I've consumed from water treated with the GravityWorks, but I've also only used the product domestically in the United States.

Read more: Platypus GravityWorks Filter System 2L reviews (6)

Top Chemical Water Treatment

Aquamira Water Treatment Drops

user rating: 4.5 of 5 (9 reviews)

“I choose a lazy person to do a hard job. Because a lazy person will find an easy way to do it.”

Reasons to Buy

  • Light
  • Compact
  • Ease of use
  • Effective

Reasons to Avoid

  • It runs out, then you buy more
  • Doesn't get rid of sediment or debris

Aquamira drops have been my go-to for water treatment for a few years now. I've used a Katadyn Basecamp gravity filter, which worked well until it just stopped one day. Pretty big and heavy in retrospect anyway. I've also used a gravity filter that I rigged up with a Platypus Big-Zip and a Sawyer Mini that worked brilliantly until it just stopped working one day no matter how hard I back-flushed the filter.  I've never used a pump filter, I can get the same results with a gravity filter with no work other than waiting for a few minutes, and presumably the filter in that would just give up one day.

Read more: Aquamira Water Treatment Drops reviews (9)

Chemical Water Treatment

Katadyn Micropur MP1 Purification Tablets

user rating: 4.5 of 5 (6 reviews)

I have used these tablets on a few trips so far, as my only method of water treatment (other than filtering through a bandana if there's obvious crud). In order to keep my pack weight down, I wanted to avoid carrying a filter. However, I didn't like the idea of using iodine tablets, decided chlorine dioxide sounded better, but didn't want to use a liquid product like Aquamira drops (too much chance of spillage). So, when I found out the chlorine dioxide was available in tablet form it sounded ideal.

Read more: Katadyn Micropur MP1 Purification Tablets reviews (6)

Bottle/Inline Water Filter

Sawyer Micro Squeeze

user rating: 4.5 of 5 (1 review)

The Sawyer Micro Squeeze is a very lightweight, compact, and versatile water filtration system with a long lifespan that will help keep you safely hydrated on the trail. You can drink directly from the water source with the included straw or filter water from the included bladder using the squeeze method or from disposable water or soda bottles using the gravity method. Once filtered it's ready to drink or store in the vessel of your choice, and you can even direct line to hydration packs.

Reasons to Buy

  • Lightweight
  • High capacity filter (up to 100,000 gallons!)
  • Filter membrane never needs replacement
  • Very compact
  • .1 micron filtration Filters out 99.9999% of Bacteria, Protozoa, and Cysts, including E. Coli, giardia, vibrio cholerea, Salmonella typhi, and microplastics
  • Includes 32-oz bladder with instructions printed on it

Reasons to Avoid

  • I would like to see an arrow printed on the filter that indicates flow direction
  • The plunger on the drinking fitting requires an extremely high effort to open up at first.
  • Instructions on packaging could be more thorough

Sawyer filters are highly regarded in the thru-hiking community, so I was anxious to put the Micro Squeeze to the test during my backpacking trip in Utah, and my upcoming bicycle tour of the USA.  Packaging: I immediately read and noted the capabilities of the Sawyer Micro Squeeze printed on the package. There is a warning on the package which states that "Boil Alerts" when issued need to be adhered to in order to eliminate harmful pathogens. The Micro Squeeze WILL NOT filter out viruses.  The Micro Squeeze Filter element is .1 micron and filters out 99.9999% of bacteria (salmonella, cholera and E.

Read more: Sawyer Micro Squeeze review (1)

Water Purifier

MSR Guardian Gravity Purifier

user rating: 4.5 of 5 (1 review)

The MSR Guardian Gravity Purifier is an all-in-one water treatment system that is ideal for groups, or people needing potable water in larger volumes. Not only removing bacteria, protozoa, sediment and particulate, MSR’s new flagship purifier also removes the tiniest viruses, while also using activated charcoal to improve flavor and reduce chemicals. The Guardian’s new purge valve quickly and easily cleans the filter to maximize flow rate, removing debris.

Reasons to Buy

  • Removes most high risk microorganisms and contaminants
  • Easy to use/Intuitive design
  • Spectacular purge hose system easily cleans purifier
  • Designed well to prevent cross-contamination

Reasons to Avoid

  • Price point high, but well justified
  • Weight could be a consideration/subjective rather than a con
  • Like many other filter systems, long-term storage protocol can be daunting

Mountain Safety Research (MSR) is no stranger to water treatment, and even taking a quick look at the Guardian Gravity Purifier, it shows. MSR has been responsibly manufacturing a host of products for over fifty years. You can read more about MSR here. At the core, MSR Guardian Gravity Purifier is its hollow fiber technology. Unlike all of the other hollow fiber core water treatment products currently available, the pore size filters much smaller particles, effectively removing viruses. This technology came about via the pharmaceutical industry, where specific molecular sizes were required to be filtered for scientific testing.

Read more: MSR Guardian Gravity Purifier review (1)

Pump/Gravity Water Filter

Platypus QuickDraw Microfilter System

user rating: 4.5 of 5 (1 review)

Without a doubt Platypus has a very clear understanding of what its customers are looking for in a water filter, resulting in the Platypus Quickdraw Microfilter. From my perspective, it is the number one hollow-fiber membrane water filter design available today for solo through hikers or anyone looking to buy their very first water filter. The well designed Quickdraw Microfilter is a hollow-fiber membrane water filter that takes a few evolutionary steps from an integration and maintenance perspective over other water filters currently available that use similar technology. Every aspect of its design is well thought out, resulting in a filter that performs well, provides multiple interfaces for dirty water containers, and can be maintained in the field without additional special tools.

Reasons to Buy

  • Solid construction and good flow
  • Is compatible with Smartwater bottles
  • Light
  • Good clear instructions
  • Clean side cap is attached with long life hinge design
  • Materials used have a nice feel/texture—Thermoplastic elastomer
  • Cap from filter mates with cap from bag
  • Can attach to multiple preexisting bottles
  • Waterproof cap designs make it easy to keep in your sleeping bag on a cold night that might damage the filter due to freezing

Reasons to Avoid

  • Tight path into filter may trap small debris that won’t easily be cleaned out with shake or backflush method
  • Round design can roll away

The Quickdraw Microfilter is a hollow-fiber membrane filter recently introduced by Platypus that from my perspective is the first filter design that really takes into account how these types of filters are actually used and maintained out in the field. While the hollow-fiber membrane used in this filter is not new, each and every feature of this filter is well thought out and delivers a design that reflects how people want to use and maintain a water filter.   The Quickdraw Microfilter is designed to filter out bacteria, protozoa, and particulates larger than 0.2 microns, but is not intended for use to filter out chemicals, toxins, or viruses.

Read more: Platypus QuickDraw Microfilter System review (1)

More Water Treatment

Trailspace reviewers have shared 640 reviews of 109 different water treatment. Narrow your search and view more specific water treatment product recommendations in these categories:

Water Purifiers

Pump and Gravity Water Filters

Bottle and Inline Water Filters

Chemical Water Treatments

Water Filter Accessories

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