Gravity filter

ELKOHUNTER

Junior Member
Joined
May 4, 2019
Messages
45
I've always used pumps, and tabs. I didn't want to spend a boatload before trying one out.
Msr bag
Msr bladder kit
Rapidpure filter.

My question is for those of you that have a gravity filter, what issues do you see? I'm going to add a 3in section below the shut off with a quick attachment for my bladder.
 

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motts

Senior Member
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Dec 17, 2014
Messages
242
How are you planning on getting the water into your "dirty" drom bag? A lot of systems use a bag with a ziploc style opening across the top so you can kind of "scoop" from your source to fill it up; as you have it shown, I imagine you would need either a decently deep pool/puddle to submerge the bag or running water to fill it up. I'm not currently using a gravity system, but I still run into the same issue when using my 4L Hydrapak soft bottle and tabs, so there could be some other trick I'm not aware of.
 
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ELKOHUNTER

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Joined
May 4, 2019
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45
Good point. Where I planned to test it I'll be by a lake. That probably clouded my view of how I was going to get water into the bag. If its shallow I would imagine I'd need a water bottle or something shallow.
 

Magnett

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Jun 2, 2016
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Having used the gravity system for years, I would say your top unfitered water bag should be like a Platypus 4L with nylon handles and a ziplock top with a capped spout on the bottom. The top opens up so you can drag it through the water source to collect water. I started with a long drop tube going from the unfiltered water bag to the filter but have since reduced it to like 12". Your MSR Dromedary will make a good clean water bag. Bad thing about filter systems is that they can freeze up in the winter and if there is water in the filter it can crack.
 

mro

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Jul 3, 2017
Messages
29
Location
CA
I have a setup very much like yours (MSR dromedary -> hose -> sawyer squeeze). I don't have a shut off valve though. To stop the flow of water, I just tuck the filter back up into the MSR webbing so it's higher than the bottom of the bag. I usually fill from lakes and hang the bag on a branch. Sometimes I use a marlin spike hitch coming off a tree and hang the bag from that.

The biggest annoyance I've had is that the bag / filter will sometimes swing back and forth from wind. Not really a big though.
 

Mule3006Elk

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Joined
Jun 17, 2016
Messages
251
Filter. Slows over time. I take mine off and shake it in the opposite direction of flow effectively backflushing the filter. Do this every time. It really helps IMO.
 

C.payne

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Joined
Feb 13, 2020
Messages
59
Location
BC Canada
I have the platypus gravity works system and really like it. The two issues I have had is that the filters can freeze up and possibly crack and also if the source water is really silty you can plug your filter pretty quick. I back flush mine every time I use it and if it is cold out I make sure to shake out the filter. I have also put my filter kit in my sleeping bag at night to help protect it from freezing.
I agree with what has been said above. It is nice to have the ziploc style bag for shallow water sources.
I use a bladder in my pack and I have installed a quick coupler on my hose where it comes out of my pack. That way I can filter water directly into my bladder without removing it from my pack. This is a big plus to the gravity systems in my opinion.
 
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Beendare

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May 6, 2014
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In Traffic
I'm done with the Gravity units.

I've back flushed mine per instructions....they still clog way too easy...and the replacement filters are expensive.

_____
 

AndySee

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Joined
Feb 22, 2020
Messages
29
I'm a huge fan of the sawyer direct thread filters, with two big Smart Water bottles. One is dirty and the other clean. If I want two clean bottles, I just chemically treat the previously dirty bottle. Lighter than nalgene and has yet to break.
 

TimberPhantom

Newbie
Joined
Apr 30, 2020
Messages
2
The only issue I have had with mine is finding a good branch to hang the top bladder from. I finally took a length of tent guy line and use it to hang the dirty water bladder from branches of different heights or stumps. The clean water bladder rests on the ground. I was going to buy the Platypus setup but already had two Camelbak bladders and a Sawyer so I made my own. The handles on these bladders make it easy to submerge them or skim them across shallow water to fill. The only other gripe I have is it takes a few minutes for the water to filter through. Not an issue if I use the time to adjust my pack, eat, etc. An advantage I see with this setup is that if one of the bags springs a leak, I can just insert the filter into my main drinking line and drink from the dirty bag
 

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Dos Perros

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Jul 30, 2015
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1,542
Location
Lenexa, KS
I have the CNOC > Sawyer Squeeze and drip water into whatever I'm running then. It works pretty well.

I will say, if it's hot and you've got three thirsty dudes it doesn't seem to filter fast enough. Last year I left my setup at the vehicle and we used my buddy's heavier MSR gravity filter and that thing can move some water.
 
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