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  • Filter life is rated at approximately 1,500 liters (depending on water conditions)
  • Replacement cartridge filters to 0.2 micron; filter meets Environmental Protection Agency standards for removal of bacteria and protozoa
  • The GravityWorks replacement filter weighs 1.9 oz.

Made in USA.

View all Platypus Replacement Filters

REI membership


Best Use Backpacking
Rated 5 out of 5 by from Best addition to AT Thru Hike This was undoubtedly the best addition to my recent Appalachian Trail thru hike. I actually spliced this into the hose for a Platypus Big Zip 3L resevoir, so that it was filtering as I drank from the resevoir. This was a recommendation from the REI team in Asheville, as it reduced the need of carrying two resevoirs (one for dirty water and the other for the clean water after it was filtered using the gravity work system). Any thru hikers that started with a pump system quickly switched it out a system like this or to water tablets. Mine took a real beating in my backpack for five months and never once had a malfunction, and I never once got sick from any questionable water sources (which there were many!) This is the only system I would use for future long distance hikes.
Date published: 2013-11-13
Rated 5 out of 5 by from Best Way There's not been a single person I've camped with that doesn't fall in love with how this thing provides water. It's my favorite piece of gear, really. Water is essential and the gravity system is effortless hydration. Such a simple concept that hasn't been fully embraced yet... My first filter lasted hundreds of runs of mountain-stream water, and only started to slow when I was forced to fill from some pollen-covered murky lakes. New filter is back to going through a liter every 25 seconds or so. For how much the (smaller) gravity kits cost, though, it makes sense to spend the extra few bucks to get some spare bags and hose instead of just the filter cartridge. The filters are justifiably overpriced - they last a LOT longer than you'd expect.
Date published: 2013-06-30
Rated 2 out of 5 by from Replacement had issues I used the original filter for a group of 4 for 500 miles on the Colorado Trail last year - it worked great most of the time and after a couple hundred gallons the original slowed down to 20minutes/gallon (not great, but manageable). One thing that is critical is clearing the air out of the filter by backflushing each time you use it to get optimal speed. Even with regular backflushing, the performance of the filter slows over time and it is frustrating that there is no other way to clean it since it is completely sealed. However, since this filter requires minimal active work, you can filter as you rest/snack. I gave several REI presentations after this trip and recommended the product (with original filter design). My wife did the Colorado Trail this year (2012), and since I didn't want any problems for her, bought this replacement filter for her trip with my son. However, after about 20-30 gallons the filter slowed way down to 40-60 minutes per gallon and was impractical to use. Kids and I joined them for the last 125 miles (total of 7 people supported by this single filter) and had to do all our filtering the night before (3+hours of filtering) and carry all water for the day (sometimes 20lbs of water) because there wasn't enough time to do it throughout the day as we crossed water streams - very frustrating. We backflushed several times and worked hard to remove air to optimize performance, but still couldn't get more than 1 gallon every 40+ minutes through it. I'm getting another replacement filter, and hoping this one performs better.
Date published: 2012-08-06
Rated 5 out of 5 by from What was I thinking with a pump filter With all my fishing, hunting, and backpacking excursions I never leave without a filter, just in case. I have been using the same hiker pro for the past 10 years and love it but thought it was time to get something that didn't require so much effort when we have a big group on backpack trips. A employee and REI told me about this unit so I gave it a try. After the first night where I filtered 2 gals, I thought this thing is too good to be true, "I bet it will clog." However, I used it for a three night trip, without backflushing and it never clogged. I backflushed it when I got back home and then used it the following weekend, with no problems. With the hoses it is the same size as a hiker but quite a bit lighter, so this new unit will now go everywhere with me. My only concern is how it will hold up over time as I know the internal straws are fragile. Overall I couldn't be happier. Thanks!!!
Date published: 2013-06-20
Rated 5 out of 5 by from A backpacker's best friend This system easily supported 24 backpackers on a trek. As far as a group filtration system, I could find no better for the price, weight, and functionality
Date published: 2011-05-09
Rated 4 out of 5 by from Great Filter I have had the gravity filter for a couple of months, and i have had great results. It isn't any faster than a pump filter, but it is nice to walk away while it works. I couldn't see myself going back to a pump filter. I do have concerns that larger chunks of debris will lodge and clog the input. It would be nice to have some prefilter feature. I bought this item in pieces; i did initial buy the hose kit. The filter barb and oem hoses seem to be 3/8", while many other filters use what i think is 1/4"; so make sure you have the right size hose.
Date published: 2016-12-08
Rated 5 out of 5 by from GREAT Filter I went on a 40 mile backpacking trip with 6 Venture Scouts. These are teenage boys that eat and drink ALOT. I bought this filter after being advised to try this one from my Sweetwater that I have always used. This filter was great when I got into camp. It would filter the 4 L of water in less than 5 min and the water was great.
Date published: 2015-07-22
Rated 5 out of 5 by from Excellent product I just came back from a 3-day trip in the slot-canyons east of Zion NP, Utah. Whenever we found a spring this filter would fill up four of us in just a few minutes. It's brand-new now and filters a liter in under a minute. Very impressive.
Date published: 2012-05-07
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How long do these last with infrequent use? I know that can vary, but I'm curious if they have an overall expiration date once put into use (i.e. will the filter material deteriorate after a certain point, as opposed to just clogging and slowing down).

Asked by: dprez
The Cleanstream Gravityworks filter does not come marked with an end-of-life date stamp, and if you were to leave it on the shelf unused, it would not deteriorate. While in use maintenance and storage become factors, and you will want to separate out silt and sand before uses and back-flush the unit every 6 liters of water. They cartridge is designed to work for 1500 liters, however, the water variance you may see and flow rate begin to slow after 1000 to 1200 liters of water.
Answered by: REIservice
Date published: 2017-05-04

Is the tubing adapter the same as the MSR replacement cartridge? I plan to use this one in its place...

Asked by: Tahquito
The tube attachment on this replacement cartridge is the same size as a tube attachment on an MSR filter.
Answered by: REIservice
Date published: 2017-05-10

I had this filter and let it freeze overnight with water in it. Is it destroyed?

Asked by: R0acer0
The safe bet would be to replace the cartridge. Freezing the Gravity Works cartridges can permanently damage the internal fibers.
Answered by: REIservice
Date published: 2016-06-06
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