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  • System includes a 2-liter dirty collection reservoir, a 2-liter Platy bottle, GravityWorks filter cartridge, in-line adapter and hoses
  • Fill the dirty collection reservoir, hang it above the clean Platy bottle and let gravity carry the water through the filter—filtering water has never been so easy!
  • Hollow fiber filter technology offers a high flow rate of 1.5 liters per minute—that's 2 liters in less than 90 sec.
  • Filter physically removes particles, protozoa, and bacteria down to 0.2 microns in size, including giardia, salmonella, cryptosporidia and others
  • Unfiltered reservoir features a quick-disconnect valve that automatically shuts off the flow of water when hose is disconnected
  • Use the included push/pull adapter to connect the GravityWorks system directly into any Platy bottle with a push/pull cap; also works with many other bottles and reservoirs
  • Clean the system by simply holding the filtered-water reservoir above the unfiltered-water reservoir to backflush the filter
  • Taste-free reservoirs and silicone hoses ensure great-tasting water
  • Platypus GravityWorks 2-liter water filter system reservoir kit weighs only 11.5 oz.

Made in USA.

View all Platypus Gravity Water Filters

REI membership


Best Use Backpacking
Filter Type Gravity
Filter Medium Hollow fibers
Removes/Destroys Protozoa and Bacteria
Pump Force Not applicable
Pump Strokes Per Liter Not applicable
Output 1.5 liters per minute
Housing Material ABS plastic
BPA Free Yes, Yes
Field Cleanable Yes
Dimensions Filter: 3 x 7.4 / reservoirs: 19 x 8/13.5 x 7.5 inches
Weight 11.5 ounces
Rated 4 out of 5 by from Test It Before You Go I used this water filer on two backpack trips and only ran clear water through the filter. It never flowed at the rate indicated, that being 4 liters in 2.5 minutes. In fact, it got to the point on my 22 day backpack of the John Muir Trail that it took ONE HOUR to produce 10 liters of water. I never froze nor dropped the filter cartridge. I did see someone else's on the trail working at what I suspect was the specification rate. I also developed a small hole in the dirty bag, thankfully in the upper inch of the bag. So it didn't significantly affect the ability to filter 2 liters of water at a time. My chief piece of advice to anyone purchasing this product - TEST IT FIRST AT HOME TO DETERMINE THAT IT FILTERS AT THE RATE SUGGESTED. It was a huge waste of time having to take an our out of my day to filter 10 liters of water on my JMT trek.
Date published: 2013-08-08
Rated 5 out of 5 by from Best Water Filter Ever! This is by far the best filter I've ever used. It is faster and easier than anything with a pump, and it is so light and compact I take it everywhere. Some people here are complaining about flow rate, air locks, etc. If you backflush regularly you won't have any problems at all -- read the instructions! I have filtered silty, dirty water from a livestock infested area for a group of people for days on end with no problems at all. One of the best parts of this system is that you can carry a lot of water back to camp with you and filter / use it as you need it. You can also use just the dirty bag and a Platy adapter as an ultralight system that filters water directly into the reservoir in your pack, right through the hydration tube. The only thing I don't like is that the filter can be damaged if it's frozen. That's easy to deal with though, just keep the filter in your tent / pocket when it's cold out.
Date published: 2013-09-12
Rated 5 out of 5 by from Little effort w/o moving parts As an AT hiker, water is never guaranteed. This works as a great filter. If you are near a reliable water source, this will even work as a "sink" (I have older, 4Liter series, worth it for me). After filtering, hang clean bag so that end of hose is 12" off the ground. Now you can prop the cutoff valve open (I used a twig) and have running water to wash pots, utensils, and face. The seller for me was no moving parts to break in the field. When your pump handle breaks off or inner chamber of pump filter cracks, you're up a creek without a filter (pardon the pun). This gravity filter can be repaired with super glue, either to the hose or bags. The learning curve is the backflush technique. Watch the videos, practice at home. If you get air in your line, pinch the "clean" hose 3" directly below the filter for a few seconds and then release. This may need to be done a few times, but soon the water is flowing great. Sleep with filter to improve life of filter/prevent freezing. I always keep twine and small carabiner in carry bag so that I have some thing to hang bag while filtering. That way I don't have to hold it will it works. I don't know the average time, but at one point I had a liter filter in 1 min 10 secs. I like it. Plus you can carry dirty water bag and have it to filter later. I'll buy again as a gift for someone one day.
Date published: 2014-02-06
Rated 5 out of 5 by from Fast & Virtually Effortless Water Filter On a recent 4-day trip this became the source of potable water for our party of three. On day two after reaching high camp it was used to quickly filter 12 liters of high lake water into a 6-liter Dromedary bag, 2-one quart water bottles with small and large caps, a Camelback bladder, and the Platy 2-liter clean bag that kept us supplied for the rest of our stay. A quick backflush burp by raising the clean water vessel to clear the air bubbles and 2 liters are done in a couple of minutes without any other effort. Then another quick backflush to prepare for the next 2 liters. The bottle adapter came in very handy for the assortment of containers that needed to be filled. I did use an empty Sawyer filter bottle to dip into the lake to fill the Platy dirty bag. I really like this filter!
Date published: 2014-08-20
Rated 1 out of 5 by from Very Disappointed I purchased the 4.0L version for a 7-day group trek (Boy Scouts) through the Weiminuche Wilderness of Colorado. The filter performed well the first few times it was used then became incredibly slow and almost useless. The water being filtered was very clean (high elevation snowmelt streams) yet it became necessary to engage in all sorts of backflushing and air removal strategies to get the filter to flow AT ALL. Doing everything we could to increase the rate we were able to get 3L in 7 minutes. It was a mistake to depend on this product and I would not recommend it to anyone.
Date published: 2013-07-06
Rated 5 out of 5 by from great product this is a great product and works well for larger groups. the filter does clog rather quickly however back flowing "clean" water the opposite direction quickly flushes out the filter.
Date published: 2013-07-24
Rated 4 out of 5 by from Awesome product This unit is awesome! I have always wanted one of these ever since I saw the 4L ones come out a while back, though most of my travels are day hikes, or weekend camping with backpacking involved. They finally came out with the 2L and this is just perfect really, everything appears to be of good quality, and things are very user friendly. Can't wait to really get some good use out of it!
Date published: 2013-06-06
Rated 5 out of 5 by from Super fast, easy to use We just used the Platypus on a hike to Lake Minotaur and were able to filter all our water super easily. I was amazed at the speed - about 1 liter in 90s or so.
Date published: 2016-07-24
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My filter is running super slow. Used murky lake water during the summer.It is no where near the max life. How can I revitalize it?

Asked by: vanc014
It sounds like your GravityWorks Water Filter System Reservoir Kit needs to be backflushed. The steps below will teach you how to backflush the filter. 1. Before the dirty reservoir is empty, disconnect the dirty hose at the quick disconnect fitting and raise your clean container above it. Allow water to run onto ground for four seconds, or until the water runs clear. 2. Lower clean container, reconnect quick disconnect fitting and continue filtering.
Answered by: REIservice
Date published: 2016-09-29

How long can a filter be used before it needs to be replaced?

Asked by: MCaldwell
The life of the filter on the GravityWorks will be approximately 1,500 liters. This can depend on water conditions.
Answered by: REIservice
Date published: 2016-12-26

Does the gravity works system include a clean hydration hose? Or is it sold separately? 

Asked by: Frishholz
This system comes with one hose to connect the "dirty" bag to the filter and one hose to connect the filter to the "clean" bag. There are no additional hoses to be used for drinking.
Answered by: REIservice
Date published: 2017-01-26

Can the clean water reservoir be used as a water bladder? If so, does REI sell the appropriate house and bite valve to fit it? Thanks

Asked by: Nick96734
Yes, you can use the clean bladder included in the GravityWorks Water Filter System Reservoir Kit as a hydration bladder. You would need to purchase the Platypus Drinking Tube.
Answered by: REIservice
Date published: 2015-09-20

I'm confused about the weight -- this is listed as 11.5 oz and is supposed to be the "lighter, backpacking version", but the 4 liter one is listed as 10.6 oz.  Is more included on this one (or more needed for the 4 liter)?

Asked by: dfscott
The reservoirs in the 2 L kit weigh slightly less than those in the 4 L system, but the included water bottle adapter, which isn’t in the 4 L water filter system, makes up for the difference in weight.
Answered by: REIservice
Date published: 2017-02-17

Will the bottle adapter fit a wide mouth Nalgene?

Asked by: Fjp78
The GravityWorks Water Filter System Reservoir Kit comes with a universal bottle adapter that works with wide-mouth Nalgene bottles.
Answered by: REIservice
Date published: 2016-07-18

Does the 2L water filter kit include the necessary fittings so that I can fill my platypus hydration unit without having to remove it from my pack? Can I do the same with other brands of hydration units?

Asked by: TheMonkeyboy
This complete kit can fill most hydration reservoirs without removing them from your pack. This is done by removing the blue adapter cap from the barb at the end of the hose and inserting the barb into the hydration reservoir tube or the shut off valve if using a CamelBak or Platypus product. The video on our page shows this method in action.
Answered by: REIservice
Date published: 2016-12-28
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