Sawyer in line water pre filter

Discussion in 'Camping Toys' started by MrPulldown, Jul 9, 2019.

  1. MrPulldown

    MrPulldown Long timer

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    anyone got something? I have turned my sawyer mini into a gravity filter. Works well, but I am trying to fit a pre filter of sorts into the system. Something like this looks like it will work, but it is too big, everything I have is in the 1/4" tubing range.
    [​IMG]
    https://www.ebay.com/itm/Tap-Adaptor-Snap-On-Water-Filter-Connector-Garden-Irrigation-Antelco-Multi-Item/262992040652?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=2586db7dede147c8bc9bdd3dec8b217d&pid=100675&rk=5&rkt=15&sd=323777453096&itm=262992040652&_trksid=p2481888.c100675.m4236&_trkparms=pageci:352c2fa8-a28c-11e9-86c9-74dbd1801aaa|parentrq:d88735a716b0aa47c56117a7ff8d2de0|iid:1

    Was considering a small in-line fuel filter, however I am concerned about the flow rate of the filter media, and the whole "food safe" aspect of the filter.

    Anyone know of a in-line screen filter with barbed ends that will fit a 1/4" tube. Ideally the screen can be easily cleaned.

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    A little back story. I have been a backpacker since I was a kid. Started with using a pump filter for many years. I have owned several. Pump filters have a strainer or prefilter located on the tip of the intake hose. 10 to 15 years ago I starter playing around with other filters and water treatments. As I spend some time in the high country where fresh snow melt is plentiful I started to use a Steri Pen (UV). Also would use polar pure (iodine). Even though snow melt is "pure" there are some bacteria that live in the sierra snow that I would like to avoid ingesting before killing.

    While on a multi day back country ski trip trip, my Steri pen runs out of batteries. Actually I had replace the lithium batteries I had in there with alkalines. Big mistake. The steri pen can only be used with liths and nickle metal rechargeables. Buddy brought a back up filter: a Sawyer mini. The sawyer is a new school filter which use hollow fiber or nano tube tech which filters down to 0.1 microns and it good for 100K gallons. I had read about this type of filter but was reluctant to use as a primary.
    https://sawyer.com/technology/
    We used this filter for 4 people over 3 days, and it proved itself. One thing to note is that the hollow tubes can be damaged due to freezing (with water in it, once used you cant get all the water out). We were very careful and kept the filter in an inside jacket pocket when not is use. Once I got back home I buy a Sawyer mini ($20) as I was so impressed.

    Fast forward a few years and I am on a backcounty ski hut trip with my son. The couple that shared the hut with us used a Platypus brand gravity filter with a hollow tube type cartridge (similar to a Sawyer). I was still using my trusted pump filter. I decided that I needed to get with the times.

    That summer before a backpacking trip I hooked up my Sawyer to a camel back bladder and connected it to a MSR 10L dromedary bag. This rigged up filter provided clean water for 6 people for 2 days.

    Over the 4th of july I went out packing for a couple of nights and brought my sawyer rig (100oz camelback to 100oz cb, no need for the 10L bladder). Was noticing that despite my best efforts to scoop up clean water I would get some debris. This debris would then superficially clog the filter, and stop the gravity flow action. A quick back flush would remedy the issue, but it would happen again after each 100oz of filtration. I did bring a Steripen prefilter, but I did not want to sacrifice a drinking bottle (only brought one). I had brought the SP pre filter it along if I could only collect water for shallow slow moving streams.

    So now I in the process of making my personal gravity filter kit, and looking for feedback and suggestions on how to get rid of the tiny bits of filter and hose clogging debris without straining my water before hand.
    #1
  2. nvklr

    nvklr Been here awhile

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    Well the first thing to come to my mind is probably size weight prohibitive for backpacking use but to to get the ideas going anyway water filter for refrigerator/ice maker.
    Good luck in your search for something more practical. OR strain the water through a coffee filter.
    #2
  3. nvklr

    nvklr Been here awhile

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  4. dpike

    dpike BeeKeeper Supporter

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    Can you use paper coffee filters as pre filters ?
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  5. applicant_255

    applicant_255 Misshapen Shaved Ape

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    Agricultural sprayers backpacks will probably have a plastic screen in them. My cheap princess auto one has one anyway, about three inches long on a slant, though this might not filter down to the level you need. Harbour Freight or Princess Auto or Tractor Supply should have a small inline screen that slips right into your quarter inch lines.

    A fuel filter would do the trick as well, certainly be available in 1/4 inch sizes with a variety of media, paper being the cheapest, brass, and plastic available, most are see-through so you get a good look at what you’re filtering out and how clogged it might be.

    If you want even cheaper than that, buy some pantyhose and line the inside of your source bag of water. Make sure to get the classy lady fine stuff and not the stripper fishnet.
    #5
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  6. MrPulldown

    MrPulldown Long timer

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    This is a garden screen. But it might do the trick. If I find a garden hose to 1/4" barb fitting set. and sandwich this in the middle. Ideally not a brass but plastic fitting.
    [​IMG]
    [​IMG]

    I can scope the water into a bottle and strain with coffee filter or even a bandanna. But the idea is to scoop up the water and go. And not have to deal with pre straining. The steripen per filter I have is basically this; a screen filter that attaches to the end of a nalgen bottle. I did bring it in case I really was filtering some gunky water, bu tnever had to use it. THe lake water was pretty clean. But getting some floaties was unavoidable.

    You know I might revisit the fuel filter. I am afraid that the paper element ones would flow too slow or intorduce contaminates to my drinking water, even though it will get filtered out. I have a handful of those. But the sintered bronze ones might have less resistance.

    In fact I use to have a inline prefilter. Can not find it anymore; must have got rid of it. But I recall that it added a lot of resistance when pumping. Since my new set up is gravity feed, I really need to limit the amount of resistance. MSR currently makes a very good silt stopper. But I think it will flow too slow.
    [​IMG]

    I think I am go to the hardware store afterwork today and see what I can find.
    #6
  7. nvklr

    nvklr Been here awhile

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    “ If I find a garden hose to 1/4" barb fitting set. and sandwich this in the middle. Ideally not a brass but plastic fitting...”
    Maybe in the drip irrigation area of hardware store.
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  8. nvklr

    nvklr Been here awhile

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  9. MrPulldown

    MrPulldown Long timer

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    That's the plan. As you can probably tell, I think this kind of stuff is FUN, and half (or more) of the reason why I am a gear weenie.
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  10. 2 SPOT

    2 SPOT bring the rape whistle

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    male and female plastic hose barb adaptors with a foam plug in the middle.
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  11. hamiamham

    hamiamham Been here awhile

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    Google pre-filter for sawyer mini and you will find literally 100 different ways people use everything from a fine sand to pantyhose to those gold/metal coffee filters to fine mesh screens to filter water. When I owned a boat we had a fuel funnel of sorts with a few mesh screens in it to filter fuel before we put it in the tanks. Not sure how patient you are but you might be able to scoop a bucket full of water, let it settle, and basically ladle the clean(er) water off the top.

    You mention a gravity system so I imagine you have a bucket or something at the beginning of the system to get the party started. You could stretch some pantyhose over the top of that or find increasingly finer mesh screens to put into the container itself.
    #11
  12. nvklr

    nvklr Been here awhile

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    So what did you com up with?
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  13. MrPulldown

    MrPulldown Long timer

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    1/4" barb to 1/2" NPT male was the corner stone piece. Couple of mesh screens. Could not find a female 1/2" to barb. So I found a threaded cap, and a 1/8" npt male to barb. Drilled and tapped the cap for 1/8" npt. The filtering surface area is based on the 1/8" orifice, so not ideal. Flow direction is to the threaded cap. Figure half to eighth inch was the better direction. Also the 2 screens were of different diameters, and the bigger is jammed in the cap, and the free floating screen the first to contact dirty water. This flow direction is easier to clean.

    About $8 from the world's most expensive hardware store.

    Garden/irrigation stuff had some screens with built in rubber gaskets for garden hoses. That is what I based my assembly off of. Running straight garden hose stuff would have required a bunch of size reducing.

    Dripping irrigation stuff only has filters on the main supply lines. Big stuff.

    20190713_153948.jpg 20190713_153935.jpg 20190713_153921.jpg 2019-07-14 14.50.39.jpg
    #13
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  14. Siki

    Siki always n00b 2 sth

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    same diy sawyer gravity setup here made of 2 bladders, fine pipe screens, hose in "top" dirty water bladder is not right at the bottom where heavy sediment sits but rather 5 cm up, so it doesn't clog the screen right away, works like charm for days
    #14
  15. MrPulldown

    MrPulldown Long timer

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    got a picture of your set up.
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  16. Siki

    Siki always n00b 2 sth

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    20180926_124814.jpg
    here you go, not finetuned in this pic, but at least it shows it is used :)
    this kept two people going for few days
    #16