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  • Purifier removes 99.9999% of bacteria, 99.99% of protozoa, and 99.999% of viruses, while purifying an impressive 18,000 liters of water over its life
  • Advanced ultrafiltration membrane removes virtually all bacteria, protozoa and viruses, including common contaminants such as Giardia, salmonella, Cryptosporidium and E.coli
  • Gravity-powered ultrafiltration membrane technology uses no chemicals, batteries or moving parts to purify water
  • Purifies 18,000 liters / 4,755 gal. of water to 0.02 microns; flow rate of 9 - 12 liters (2.4 - 3.2 gallons) per hour of purified water
  • Roll-top dry bag is lightweight, compact and easy to fill; fill-marker windows on bag display water level
  • Included shoulder strap makes carrying easy, while also enabling the bag to be hung from a tree
  • Designed to handle turbid and muddy water
  • Purifier is easy to clean in the field, thanks to integrated back-flush bulb
  • Easy-to-remove, 80-micron pre-filter inside bag; also includes extra pre-filter screens
  • Included drawstring stuff sack provides easy storage and carrying
  • All materials are BPA-free and FDA-compliant
  • For every LifeStraw filter purchased, a child in Africa will be provided with safe drinking water for an entire school year


View all LifeStraw Gravity Water Purifiers

REI membership


Best Use Camping
Filter Type Gravity
Filter Medium Ultrafiltration membrane
Removes/Destroys Protozoa, Bacteria, and Viruses
Pump Force Not applicable
Pump Strokes Per Liter Not applicable
Output 10 fl. oz. per 90 sec.
Housing Material 200-denier nylon with thermoplastic urethane lining
BPA Free Yes
Field Cleanable Yes
5 liter
Bag: 17 x 10; hose and purification cartridge: 44 inches
12 liter
Bag: 33 x 13; hose and purification cartridge: 48 inches
Weight 13 ounces
Rated 5 out of 5 by from Great base camp Filter I've been using the LifeStraw Gravity Filter for three weeks now for all of my drinking and cooking needs, and I must say, I'm impressed. Though the water I'm using is pretty clean to begin with, there have been no clogging issues, which can't be said about all gravity filters out there. It has an anti-clogging pump which I used once when the water started to slow down. And the directions for use, including cleaning, are printed on the bag (English only). Not sure if you'd want this baby on an ultralight backpacking trip, but if you've got three or more people to take care of, the extra weight vs pumping time + work would be well worth the extra pound.
Date published: 2015-08-06
Rated 1 out of 5 by from Large, cumbersome and impractical Not to mention, I couldn't get it to work all weekend. Thankfully my boyfriend had his own filter so we didn't go without, but despite my best efforts, his and those of a few people on the AT, it never produced more than a trickle. Even if it did flow properly, I still find the design to be troublesome. I can see where this design may work well where there is a river or other large body of water, but there were times when there wasn't enough water to submerge the bag (or a stream under which to hold the mouth) and that's not a situation I want to be in again. I returned the LifeStraw bag after my weekend on the AT and purchased a Katadyn Hiker Pro.
Date published: 2016-07-23
Rated 5 out of 5 by from Great water option I have used many pump filters over the years. My "go to" has always been the Sweetwater. No more. The Lifestraw gravity filter is now my go to. A minor defect that did not impact safety or performance meant that I was able to "abuse" the unit for a week in the Boundary Waters (An area that routinely requires extra effort to keep pump filters working up to par). I found the Lifestraw nore than up to the task. After several days of use, without following the recommended backflush and cleaning routine, the flow rate did not diminish. This is lighter than the pumps I have used. Gravity (not me) is doing all the work to move the water. If you are comparison shopping, be aware that other filters let nasty stuff like virus pass through, where this one does not. The prefilter did an exceptional job of handling the less than pristine lake water.
Date published: 2016-07-17
Rated 5 out of 5 by from Lab tested results and easy to use I have tried many filters and I really like this product. The instructions are straightforward and clear and it even has the basic instructions printed on the bag that stays with the filter. The two reasons I chose this product was for its ability to filter out viruses (from the 0.02 micron filter size)and its batch filtering capacity (12L at a time with no pumping). I understand the bacteria and E. coli can be filtered out with a less expensive filter, but I like the safety factor. I went to a lab with the filter and some local lake water to have it tested. The raw lake water tested positive for both coliform bacteria and E. coli but the filtered lake water tested negative. The filtered water passed all standards for our city water. The only negative part of this product is the design of the shorter “clean” exit tube. It make sense that the tube be shorter than the backflush/dirty water valve to prevent contamination, but it’s just a little annoying during setup. It forces you to choose your hanging spot a little more carefully and adjust the strap length so the filter hangs just above where you have your clean water bottle/pitcher. This was the only thing it takes getting used to, but I will still recommend this product to anyone.
Date published: 2016-04-25
Rated 1 out of 5 by from did not work I thought I was buying the best, but I could not get it to work after repeated tries. The water dribbled in a tiny inadequate stream. The instructions were also not clear, so it was hard to tell if I was doing something wrong.
Date published: 2016-02-15
Rated 5 out of 5 by from Great for hiking and camping trips This is a great product, packs up small so not to take up too much space in your pack. We used it on our latest hiking/camping trip and is worked great. Saved us from having to pack in water for our trip. We filled the bag with melted snow and just let is run into a pot and within no time we had plenty of drinking water.
Date published: 2017-01-10
Rated 4 out of 5 by from Awesome Great product Can't wait to use it camping Wanted one for a while.
Date published: 2017-03-30
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So if the hose and purification filter need replacing, how and where can I go about doing that?

Asked by: coronadon
We do not carry replacement tubes or filters for this purifier.
Answered by: REIservice
Date published: 2017-06-22

Other than the water input container (collapsible bag v. rigid plastic) what is the difference between the Lifestraw Family and the Lifestraw Mission? Are the actual purification cartridges different? 

Asked by: Kallah
The reservoir is the main difference between the Family and the Mission. They use the same filter element.
Answered by: REIservice
Date published: 2017-06-25

I tried using the bag at home and just filtered some tap water. However, the chemical taste from the bag was so strong that I didn't want to drink the water. Does that eventually go away, or am I better off with a different product?

Asked by: Ruth
The chemical taste will eventually go away after use. We also recommend cleaning the bag and the purifier by following the cleaning instructions in the user manual. This will also help.
Answered by: REIservice
Date published: 2017-04-27

Can you speak to the flattened, packed dimensions of this unit, as if it was stored most efficiently in a backpack?

Asked by: diga
Its packed dimensions are just under 12 inches by 4 inches by 5 inches when stowed.
Answered by: REIservice
Date published: 2017-06-02

The advice column on International Travel does not List the LifeStraw as a purifier. Is this a new product since the article? Is it truely a purifier?

Asked by: cgarai
The Mission Gravity Water Purifier is in fact a purifier as it has the ability to eliminate protozoa, bacteria and viruses.
Answered by: REIservice
Date published: 2017-01-05

How do I know when the filter is no longer purifying the water. This would be essential to know in certain areas of the world.  Is the filter replaceable, or just the pre-filter screens (for solids?) and therefore not reusable after the 18k liters? 

Asked by: Swivelable
The flow on the Lifestraw Mission will drop off considerably when the filter needs to be cleaned. As it works by physically catching contaminants, it will continue to filter until it is completely blocked up. A simple blackwash will remedy the filter at that point, which last a very long time. You will need to contact LifeStraw about a replacement filter element should you need it.
Answered by: REIservice
Date published: 2017-01-30

Is there a place to purchase an additional bag if needed?

Asked by: dev428
We do not sell replacement bags for this purifier.
Answered by: REIservice
Date published: 2017-06-20
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