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  • Platypus - GravityWorks 4.0L Filter System - One Color

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  • Platypus - GravityWorks 4.0L Filter System - One Color

Platypus GravityWorks 4.0L Filter System


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    13 Reviews


    The easiest water filtration system around

    If the GravityWorks 4.0L Filter System is pretty dang easy to operate, and there are plenty of devotees who can't get enough of the world's simplest water filtration system. Just fill one of the Platy Zip bags with water, place it above the empty bag, open the hose clamp, and let gravity do the rest. In 2.5 minutes, you'll have four liters of clean water, and if camp is far away, fill the other bag to carry back with you and clean when you need it. Open the hose clamp to dispense water, and shut it to stop the flow. To clean, simply reverse the bags for four seconds, running water through the filter in reverse. That's seriously it.

    • Two 4L Platy Zip bags
    • Filters 4L in 2.5 minutes with no pumping
    • Meets all EPA guidelines for removal of bacteria and protozoa
    • Shutoff valve for easy use
    • Four-second reverse-flush cleaning
    • Item #CAS001G

    Tech Specs

    Purifying Element
    hollow fiber
    protozoa, bacteria, particulate, giardia, cryptosporidia, E. Coli, salmonella, cholera
    Cartridge Life
    1500 L
    4 L / 2.5 min
    Field Cleanable
    yes, backflush
    3 x 9.5 in
    Claimed Weight
    10.75 oz
    Recommended Use
    hiking, camping, backpacking
    Manufacturer Warranty

    Tech Specs

    • Reviews
    • Q & A

    What do you think about this product?

    Have questions about this product?

    Fast and amazing product

    • Familiarity: I've used it once or twice and have initial impressions

    Just used this over a weekend in the Pacific Northwest. This was super easy to use, produced a large amount of water quickly, and was 4 times faster than the pump style filter a friend was using.

    Excited to use it

    • Familiarity: I've used it once or twice and have initial impressions

    I purchased this filter system after owning the Platypus hydration bladder for a few years. I love the wider opening at the top for filling and cleaning. When I was looking for a filter system, I stuck with what I liked and went with the Platypus. This will live in our camping box for this summer and I can't wait to use it.

    Sent it to family in PR after Hur Maria

    • Familiarity: I gave it as a gift but have feedback to share

    Family reports that the system works great and its easy to use. After Hurricane Maria, the family needed a way to filter every drop used for household consumption, and this system has worked like a champ to make sure the water filters out the bacteria that causes leptospirosis. It's been a life or death situation and I'm happy to report everyone has been in good health after drinking the water filtered with this system.

    Convenient and Quick

    • Familiarity: I've used it once or twice and have initial impressions

    I have used this a couple times backpacking in Kentucky. It filters high volume at great speed and is lightweight. Murky river water came out clear (and safe, I assume, as we did not got sick.) The wide opening helped capture a trickle from a rock overhang. So far so good.

    Excellent lightweight water filter

    • Familiarity: I've put it through the wringer

    This is an overall excellent water filter. I have found it particularly useful on extended backpacking trips. It is totally worth the water weight it will save you. With this, I just about never find that I have to carry more than a liter or two of water, unless I am worried that water sources will be scarce.

    The filtration is very easy and intuitive. The buckle on the top of the bag makes it very easy to hang from a tree branch, so that you don't have to stand there holding the bag.

    The filtration is quite fast. It takes only a minute or two to filter 4 liters of water, so long as your filter isn't damaged or significantly clogged.

    Buying replacement parts is very easy. At the same time, the number of parts can make losing the parts somewhat easy. I know I lost the cap to the clean reservoir once (I did find that a regular disposable bottle cap from bottled water or soda you buy at the store can fit on just fine). I also believe they could design this using one less tube (likely the one leading to the clean reservoir), but I could be wrong, and they may have thought of that already. I would really like to find a way to feed it directly into my MSR Dromalite reservoir.

    Be careful not to filter freezing or near freezing water. You will damage the filter. I learned that the hard way. This filter isn't great for alpine environments for that reason. If you are near snow you can just melt that. Otherwise, you will have to put the water on a stove first to melt any of the frozen water, which can be a lengthy process.

    One complaint I have is that the tubes are designed with a sort of material that seems to just be a magnet for dirt and debris. I have found this kind of annoying.

    All said, this is an amazing filter that will clean out any bacteria and debris leaving for great tasting, clean water (note, viruses can still get through).


      After using a MSR hand pump to filter my water, I decided to give a gravity filter a chance. Needless to say, it has made filtering water much easier and extremely convenient. Although it can be hard to get the dirty bag filled up with smaller water sources, a scoop of some sort has fixed that problem. I also love how I can removed the clean hose from the filter and use it to fill whatever I need, whenever I need it.

      This thing is amazing!

      • Familiarity: I've used it several times

      I have used the 2.0L which is what made me want the 4.0L. The reservoir is especially nice. This packs up pretty small and filters/holds a lot of water. Great for groups and needs little effort to use.

      Gravity is King

      • Familiarity: I've put it through the wringer

      I will never use a pump filter again after using one of these. No more crouching by the creek furiously pumping water into Nalgene after Nalgene. Just fill the dirty water bag up, hook it up to the filter and clean water bag, then forget about it for a couple minutes, boom 4 liters of water.

      We used the gravity filter on four day trips for 15 weeks. It never failed us, never got clogged, and with 4 people we always had enough water. When water began to get scarce up high we could use the bags to carry 8 liters of water up to camp. Like previous reviewers, you need to be careful of the filter freezing at night. As far as durability, I hauled mine all around Thailand and Cambodia in the bottom of my pack for 7 weeks and it still works like a charm.

      Platypus GravityWorks System Rocks!

      • Familiarity: I've put it through the wringer

      I've been using the Platypus GravityWorks filter system for over four years and it may be the best backcountry water filter system out there. It's light (under 11 oz), fast (4 liters in 2-1/2 minutes) and flexible (you can carry up to 8 liters into camp).

      I use the clean reservoir as my hydration bladder, thus eliminating the weight of my 4 oz hydration bladder. The performance specs (1.75 liters per minute) are as good as the fastest pumping systems out there. And while the water is filtering - by gravity - I can take care of other backpacking tasks (try doing that next time you're pumping 4 liters of water by hand). And... with two 4 liter reservoirs (one "dirty", one clean), you can carry up to 8 liters - useful when you're camp is away from a water source. Lastly, this system is super-convenient for dispensing clean water at camp: Hang the 4 liter clean reservoir and use outlet tube and shut-off valve to fill water bottles, wash hands, etc.

      The magic in the GravityWorks filter cartidge is its hollow glass fiber technology. The tiny glass fibers filter to 0.2 microns to remove bacteria and protozoans (i.e. giardia). But... hucking a glass fiber filter around the backcountry comes with some caveats: 1. Treat her gently - the ends are protected with foam rubber, but a slam to a rock might cause damage; 2. Protect from freezing (I keep my filter in the foot of my sleeping bag when overnight temps drop below 32 deg); 3. Carefully follow Platypus' instructions for backflushing air bubbles (air bubbles being the scourge of hollow glass fiber filtration).

      I've backpacked for over 25 years and have previously used First Need Deluxe, Katadyn Pocket, Katadyn Hiker and MSR Hyperflow pump-type filters. I won't go back.

      GravityWorks 4.0L Water Filter

      The GravityWorks? 4.0L Water Filter is the light and pump-free way to collect, filter, transport and dispense water anywhere. This video includes information on use, design, care, tips and tricks for using the GravityWorks? 4.0L Water Filter. All GravityWorks? filters meet EPA and NSF guidelines for the removal of Bacteria and Protozoa, including Giardia, Cryptosporidium, E. coli, Salmonella and Cholera.

      NEW! Platypus GravityWorks Filter

      The reviews keep coming and one thing is clear: the Platypus GravityWorks water filtration systems are changing how people filter water. Whether you're backpacking, car camping or even on a day hike, an ultralight and compact GravityWorks System lets you say goodbye to pumping and everything else you ever hated about filtering water. Just fill it, hang it and get back to enjoying while gravity and our advance hollow fiber filter deliver clean water at up to 1.75 liters per minute. Welcome to the future of filtration

      Amazing light weight, high volume filter

      • Familiarity: I've used it several times

      I used this Platypus gravity filter on a 3 day backpacking trip recently. I am done pumping water through my MSR filter! This set up is awesome. Scoop the bag in the river, hang it on a tree, go set up your tent and come back to a big bag of filtered water! In my opinion this is the best backpacking water filter on the market.

      Unanswered Question

      What is the best way to dry the reservoirs? Having some trouble getting the moisture out after use.