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Gravity fed "base camp" water filter

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  • Gravity fed "base camp" water filter

    I'm trying to find a gravity fed water filter/purifier for a base camp setting--something you can hang and let fill a container rather than having to pump.

    1. As I mentioned in the other thread, I had bought the Katadyn model base on various recommendations, However, that lacks a prefilter and the filter cannot be backwashed and we found it slowed to a trickle after only a few fills. However if we put the filter element in a Katadyn pump model it would work fine, so it was partially a case of gravity-flow not being strong enough to overcome the resistance of the filter media versus a pump that produces pressure.

    2. I then bought the Seychelle model based on a recommendation here. Using that with tap water, I get nothing but a slow trickle out of the bag--probably 4-5 hours to filter 2 gallons. Not optimal.

    3. A chat with the folks at Cabellas gave me the recommendation of the Platypus gravity-fed model. It's smaller than the others but the filter can be backflushed, I am told, but I didn't see that in the specs.

    4,. A recommendation was made to retrofit the Katadyn model with a Sawyer in-line system but I haven't tried that.

    Anyone have any experience to share here?

    I'm wondering if gravity-fed has inherent limitations of flow versus a pump system.

  • #2
    We have been using the Platypus-Gravity Works system for about six months and it is truly a good and easy product to use. Kinda of expensive ($119.95), but it does about 4 liter (max capacity) in 2-4 minutes. The rate slows down as the filter get plugged with sediment and debris. We let the water settle in the 4 liter dirty bag for a few minutes if the water is dirty to let the sediment stand on the bottom (the drain is an inch or two above the bottom of the bag.

    We have had to backwash, which just requires turning the filter around (sometimes applying a little pressure to the bag) and when it starts to flow fast we turn it back around, flush and start filtering again. Filter good for 1500 liters, which is about 350-375 uses.

    We have a katadyn hiker, and the scouts like the Platypus because you collect your water and then filter it away from the water site (in the shade or where-ever). We can also store dirty water in the bladder as a backup and then filter it when needed.

    We all like it, but our comparisons are: Aqua Mira filter - small and light, Katadyn - low capacity and slow.

    The Platypus is bulky, but works great with a group. Sometimes its hard to get water is shallow water, but that is the same with all of them


    • #3
      Apparently gravity fed filters just ain't real popular!


      • #4
        I use the platy gravity filter, has 6 trips on it. Yes you back flush big deal. Flow can be slow as the filter begins to plug......But lets face it you fill the dirty bag. hang it in a tree open the clamp, go make dinner or set up your tent or hang out around your campfire and when you return you have clean water.

        As noted, you disconnect the dirty bag and squeeze on the clean side and back flush is done.


        • #5
          From what I read on, gravity filters are the in thing these days for AT hikers (the ones that use filters, more seem to use just chemicals (Aqua mira drops), and a large group of foolhardy hikers seem to just be careful about their water source, and use no water treatment (I'm not brave enough to buy their arguments)) I bought a Sawyer 3 in 1 at the Scout shop a few months ago. I'm looking for a camelbak style bladder to use with it to convert it to a gravity filter. Gravity filters make sense to me, but I'm basically lazy. Have yet to use it in the field.


          • Basementdweller
            Basementdweller commented
            Editing a comment

            When I go backpacking lazy??? naw, just rather scoop up 4 liters of water go back to my camp and let it work while I am doing something else, even if it is watching the grass grow......I am not that interested in spending any time manually pumping water.

          • DuctTape
            DuctTape commented
            Editing a comment
            Backpackers in general do not use gravity filters as they are intended for base camp, not moving. On the AT and other trails, you will find many who use inline filters or squeeze filters. They are similar to gravity filters and can be used as gravity filters, but not all gravity filters can be used by backpackers on the move.

        • #6
          I've got one of the platypus filters, but I have to say I've never used it. I really bought it more as an emergency/disaster thing than for camping though.
          I was hoping that more folks would chime in with experiences and comments. I guess, as brewmeister pointed out, they aint too popular.


          • perdidochas
            perdidochas commented
            Editing a comment
            Read up on them on They seem to be the in thing for AT thru hikers.

          • DuctTape
            DuctTape commented
            Editing a comment
            Some AT hikers use the play filter system, but those who do, either retrofitted it as an inline filter for a hydration bladder, use the bottler attachment and squeeze it through (not using gravity), or they sit and wait. Sitting and waiting is not desireable to backpackers in general. The more popular filter (that isn't a pump) is now the Sawyer Squeeze.

        • #7
          If you are looking for something suitable for your troop trailer "base", and you want your boys to learn about solving third world problems, get in touch with your Rotarians and see if you can get a hold of a filter that sits on a 5 gallon bucket. My friend showed me one of these a couple of years ago, demonstrated it for a week, and I was very impressed.
          Pure Water For All, pure water, clean water, rotary, rotary international, Forest Hills Rotary Club, clean drinking water


          • SSScout
            SSScout commented
            Editing a comment
            Thank you. This will get passed on.....

          • qwazse
            qwazse commented
            Editing a comment
            What would really be cool, is to get a mold for one that's small enough to fire in an art-shop's kiln.
            Then the boys, with leftover coffee grounds, some silver nitrate, and the right clay could make their own.
            But I don't think it will work. The organics are in the mix to burn away during the firing and leave the clay porous. I suspect to do that, brick kilns operate at different temps, oxygen mix, and tolerances for soot.
            Then there would be the testing to prove the pond-water is microbe-free after going through little Johnny's filter.

            But, what a great way to learn STEM!

        • #8
          Just updating this--

          I did retrofit a Sawyer external filter to the Katadyn bag. Basically cut off the Katadyn filter at the base so that the bag's sole purpose is now a dirty water reservoir. Definitely not cost-effective if you are starting from scratch, but since I already had the gear and it needed a new filter either way, there was no risk. This works very well and the Sawyer filter is fast, and back-flushable.

          For new systems we will purchase, I am impressed with the Platypus gravity filter. It is a 4L system so not as big as the Katadyn, but it is very fast and easy to use.


          • #9
            Just ideas:


            Reviews of MSR



            • #10
              The MSR system is very similar to the Platypus except it does not come with a clean-water reservoir bag, for the same cost.


              • #11
                I have the Platypus gravity filter (with the carbon filter attachment) and love it. It works great, filtering two liters very quickly. And yes, I've used it hiking the AT with our scouts. I bought the one without a "Clean" bag because I already have a Platypus reservoir and itmis a little,less expensive). I saw the same one on sale at REI and bought a second. I now use both "Dirty" bags and am saving the filters for when mine needs replacement. Having the extra dirty bag allows me to fill up both bags with water while on the trail and then filter when I get to camp. The only downside is that it is difficult to fill completely from a stream or spring.