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Water Purifiers

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

The best water purifiers, reviewed and curated by the Trailspace community. The latest review was added on July 21, 2021. Stores' prices and availability are updated daily.

Recent Water Purifier Reviews

rated 4.5 of 5 stars
MSR Guardian Gravity Purifier

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. Mountain Safety Research (MSR) is no… Full review

rated 4 of 5 stars
Grayl Ultralight

The Grayl UL is heavier and more expensive than in-line filters like the Sawyer Mini or Squeeze. But when we consider that it doesn’t require a container and also filters out viruses and chemicals/odors, it shows some advantages. It’s an all-in-one solution, good for outdoor use, but perhaps even more for emergencies: for those qualities I keep one new in my bug-out-bag. I see the Grayl UL as more of an all-in-one solution to water treatment and storage than a simple filtration system. I can… Full review

rated 5 of 5 stars
Grayl GeoPress

For day hikers and overnight adventurers, fill this beauty up with water at the start of your hike and when you find a water source, drink what you have and refill the Grayl. Original reviews talked about how difficult it is to press (filter) the water, think of a french press coffee maker, not hard at all and I am quite small. I love this simple, perfect system This is an easy to use, effective, fast source of filtered water. The capacity of fresh water that is also stored directly in the french-press… Full review

rated 5 of 5 stars
Grayl GeoPress

The easiest and likely fastest filter of its caliber on the market. Takes absolutely disgusting water and turns it into purified clean, tasty water. Wife and I use this on camping trips. So super simple and fast, very tough as far as the hardware pieces go. We like to backcountry hike and camp. The $80-$90 cost for this filter, with regard to the ease and safeness of the water you get, is worth each and every penny.  Full review

rated 5 of 5 stars
Grayl GeoPress

I was gifted a Grayl by someone who knows that I have occasionally taken risks with drinking stream water on hiking trips, so far so good but it drove them crazy. This filter is highly effective, durable, no parts to hunt around my pack for, will suffice for day hikes and longer hikes and acts like a great water bottle. I love it! Full review

rated 4.5 of 5 stars
Grayl GeoPress

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… Full review

rated 5 of 5 stars
MSR Miox

Amazingly light, and extremely effective purification. I have used this for over 12 years and NEVER had an issue with it ! I have used this device for over 12 years; and in guiding groups of up to six people, I have NEVER had anyone suffer any stomach ailments or discomfort. Ever! But I do not use it the way the manual suggests. By using dirty murky water in the purification reservoir,  I found that friends' MIOX devices eventually corroded the electrodes and rendered them unusable. Instead, what… Full review

rated 3.5 of 5 stars
SteriPEN Adventurer

Unlike mechanical filters this kills bacteria, protozoa and viruses, but it will not filter out debris, so it is best used with clear water. Also requires batteries. I have used the Steripien Adventurer for several mountain trips where I was guaranteed running water. I was attracted to it because, unlike other means of filtration, it also kills viruses. The idea is simple but genius—UV light disrupts the DNA of the nasties and destroys them and/or disrupts their reproductive potential. That said,… Full review

rated 5 of 5 stars
SteriPEN Classic UV Water Purifier

SteriPEN is an excellent handy tool for the right applications. Extremely easy to use, easy to carry, fits in a small pocket or attaches to one's belt or backpack strap, and can be used when out camping, but also in a restaurant in a cup of water, and in many water bottles, one can turn the bottle upside down, with the pen acting as a plug, while doing sterilization. It appears to have been developed for military application, to my memory, and that's a pretty good recommendation as to efficacy. … Full review