Finally! The perfect backcountry gravity bag filter? Airborne Outfitters Bitterroot

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
I've been dreaming about the perfect backcountry gravity style filter for a long time. Imagine rolling into your campsite after hiking in, dipping a bag into the water source near camp, and by the time your shelter is set up, you've got 6-12L of clean water waiting for you. I figure it could save between 1/2 hour and 45 minutes a day (depending on what pump filter you normally use), and a big hassle. Less time spent in camp means more time on the mountain hunting.

I've tried a couple systems over the last few years without much success. I found most of the filters to be cheap, resulting in very unreliable flow rates over the course of any extended trip. Long story short, not one of them have I ever trusted enough to rely on for an extended backcountry hunting scenario.

I was in the process of testing my own pieced together system last year, when I heard about a new startup company called Airborne Outfitters. This is a passion project by Jason Evatt, Lt Col. USAF. Now in retirement, his company is dedicated to putting the best gear in the packs of our Boys overseas, and it just so happens that there's a lot of crossover use for the backcountry hunter. Enter the Bitterroot Bag.

The Bitterroot accomplishes everything I was hoping for a Bag filter and more. Keep in mind, this was designed primarily for the military. I am going to suggest a few modifications to the system to make it perfect for my needs as a backcountry hunter, but its highly adaptable to different scenarios. These were my considerations:

1) The filter has to be high quality, with a good flow rate and an easily replaced filter cartridge.

The Bitterroot comes with the Aquamira Frontier Max. This is the perfect inline filter for the job. It integrates with the Aquamira "Universal Quick Connect" (UQC) system, which makes it perfect for customization. Airborne Outfitters sends the unit with the "red line" series filter installed. I recommend purchasing a couple of the "green line" series filters instead. The red line filters make perfect sense for the Boys overseas, where they might be encountering all sorts of nasty viruses ect. The green line filters are plenty safe for backcountry use in the US, and will provide a significant flow rate increase. I also carry one replacement cartridge with me when I'm relying on the Bitterroot as my primary water treatment. The cartridges re less Than 1 oz. These are available on Amazon.

The Bitterroot has a priming bulb above the filter, which solves the flow rate problems I've encountered in other systems. This allows you to prime the water lines, creating the proper vacuum to pull water through the filter. Last season, I filtered about 130L of water through one "green line" filter over the course of several backcountry fishing and hunting trips before the flow rate was slow enough that I needed to swap filters.


2) Must integrate with sensible camp water storage solutions.

I've always preferred to use the MSR dromedary bags for camp water storage. They come in 2L, 4L, 6L, and 10L options. I usually carry a 6L or 10L bag for camp water, and they've never let me down. In order to get the most out of a bag filter, I wanted to be able to direct connect the clean water hose from the hanging filter to my MSR bags. This way, I don't have to babysit the water filtering process. I can dip the dirty water bag, hang it, connect it to my big MSR dromedary, and walk away. This is where the Aquamira UQC system comes in really handy. I purchased an extra male/male UCQ adapter, which plugs directly into the clean water side of the Frontier. To this, I connected about 3 feet of the clear tubing. Now I just needed to connect that hose to my MSR bag. I needed a cap with the correct thread pitch to fit onto my dromedary, but with an open exit port sized for standard tubing. I tried to do this several ways, but ended up purchasing a "hydration kit" from MSR, designed to convert the dromedary bags into a camelback type system. I cut away the bite valve and tubing, and connected the cap to the male/male UQC adapter via the 3 feet of tube. With a little ingenuity, I'm sure you could rig something very similar to this with any other brand of water storage bag.

One full dip with the Bitterroot fills a 10L dromedary with extra to spare. Two 6L Dromedary bags are ideal.

The Bitterroot comes standard with a long section of hose between the priming bulb and the bag itself. This is so it can be used as an on demand system, much like a camelback. For example, a person could dip dirty water, roll and secure the top of the bag, connect up the filter lines, and put the bag of dirty water directly into their pack. The tubing would feed through the hydration port on the pack, and the filter would sit in-line with the system. Then, you could use a UQC adapter to connect a bite valve to the Frontier. I don't ever use the bag in this way, so I made a modification to this part of the system. I cut the rubber tubing to about 8 inches between the bag and the priming bulb. This creates the right overall length so when I hang the bag at head height, the MSR dromedary lays on the ground directly below the bag. Its much more manageable this way, cuts some extra weight I don't need, and I think it promotes good water flow.

I also added an alligator clip to the section of hose above the priming bulb. This allows me to shut off the water flow when my dromedary bag is full of clean water, but the Bitterroot still has water in it. I can swap to another empty dromedary, or just leave the extra water in the Bitterroot for later filtration without spilling water everywhere. Unfortunately I haven't been able to find anywhere to purchase these. I got mine from an old Katydyn bag filter I had laying around.


3) The whole system needs to be lightweight and durable.

I cannot speak enough about the durability of this bag. I abused mine over and over and it's as good as new. One of our elk camps this year was high on a ridge. We were dropping 500ft to a flowing seep, dipping the Bitterroot in the stream, rolling and fastened the top of the bag and carrying it 3/4 mile back to camp. It was slung over the shoulder, set on the ground, ect ect. I have complete confidence that its not going to fail.

I stuffed all the parts into an old Katydyn filter bag I had laying around.
After modifications, the whole system weighs in at 13oz on my scale. Not bad!

The Bitterroot has also been designed to fill other roles. It can be used as a dry bag during a pack-In for extra protection of down sleeping bags/jackets. It also comes with a specialized piece of tubing designed for blowing up sleeping pads. I tried this out, and it works great. Some people get very light headed when blowing up sleeping pads/pillows at high elevation, and this could be a real help if that bothers you. For the extra 1.5oz, I'm probably going to leave it at home.

There are limitations to this system. I would only bring this as my primary water treatment if I am going to a place I KNOW for sure has a clear flowing water source. Some of my hunting areas do not fit the bill. Sometimes water sources are seeps that must be dug out and carefully filtered with a pump or straw style filter. This system is obviously not suited for such places. I'm often hunting with a partner, so one of us can carry a reliable pump style filter such as the Katydyn Hiker Pro, while the other packs in the Bitterroot to handle camp water. This way we get the best of both worlds and cover our bases.

The Frontier max normally comes with a bite valve attachment, which allows it to be used as a "straw" Unfortunately Airborne Outfitters doesn't include that attachment with the Bitterroot right now. I purchased a Frontier in 2019 when I was putting together my own gravity system, so I have one laying around. It's worth noting that you can pull the Frontier out of the Bitterroot, add the bite valve and throw it in your pack. If i am using the Bitterroot solo and as my primary water treatment, I'll usually do this if I'm leaving camp for a long day loop.

I've reached out to Jason about all the modifications I made to the system. He was very receptive to the feedback, and Airborne Outfitters is now in the process of configuring a version of the Bitterroot specifically for backcountry hunting. Keep that in mind if you're thinking about purchasing.

I think the Bitterroot is best suited to base camp type scenarios, when you're coming back to the same camp for days at a time. In these situations, it's going to save you tons of time and effort. With a little imagination, it can be customized to fit your style and needs. Made in the USA by a veteran owned company is icing on the cake! Bitterroot bags are available at Airborneoutfitters.com

a7d5ae3c949c5cf07cd52606b3ff0548.jpg

Priming bulb unit after modifications. Cut hose back to 8" and added alligator clip
ab422c37878ef3a4f5f94de0033f75b7.jpg

Connection from the Frontier to a MSR Dromedary, via UQC + hose
ecb99d0010179254418210c1a47db8a7.jpg

a5079b5520137b5626461b2543504284.jpg

Bitterroot system after modifications, with a 6L MSR Dromedary. I have it hanging at head height by a small loop of 550 cord
82f809a040ebb6ff9b05980363828977.jpg

Everything tucks into a Katydyn bag
4777a4b1b01286a42323a57763760909.jpg

13 oz!
ab0dcb075f9e538ed1fe12712cf7fe2a.jpg

This is the piece designed for blowing up a sleeping pad, using the bag like a bellows.
33506d85d35c4f95d108a69e89a1d87f.jpg

Frontier with bite valve for use like a LifeStraw
 
Last edited:
OP
Jake Larsen

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
you had me entertained until the $145 price tag.
How much do most of us pay per day on the average 6-10 day backcountry hunt? If this system saves me an average hour per day in water treatment, that's an extra 8 hours of hunting on a 8 day backpack hunt. I get that it's not going to be for everyone, but this does something nothing else does thay I've ever seen or tried. That's worth a premium price to me! I've spent a silly amount of money in the last couple years trying to accomplish what this system does perfectly...

Sent from my Pixel 3 using Tapatalk
 

Smokeslider

Senior Member
Joined
Dec 17, 2018
Messages
114
Location
OR
How much do most of us pay per day on the average 6-10 day backcountry hunt? If this system saves me an average hour per day in water treatment, that's an extra 8 hours of hunting on a 8 day backpack hunt. I get that it's not going to be for everyone, but this does something nothing else does thay I've ever seen or tried. That's worth a premium price to me! I've spent a silly amount of money in the last couple years trying to accomplish what this system does perfectly...

Sent from my Pixel 3 using Tapatalk
Cool, good luck
 

BRTreedogs

Senior Member
Joined
Nov 16, 2017
Messages
3,718
Location
Central Oregon
Ok so this is a real question.

How is this different then the platypus system?
Other then the priming bulb i don't see how it's different.
Looks more heavy duty. Price isn't much more.
But I just can't tell how its totally different.

But I also don't use the platypus system.
 

Moserkr

Senior Member
Joined
Feb 26, 2020
Messages
515
Links broken and even googling them doesnt bring up this magical expensive system.

The one takeaway from your “review” is that a siphon bulb will make my inline filter work better whether its on a gravity filter or part of a true inline filter direct from a bladder. For around $10 i can get the siphon bulb off amazon and pair it with a sawyer filter, with any of the already modified filters systems i got. So for that idea, i thank you.
 

FishfinderAK

Senior Member
Joined
Sep 25, 2015
Messages
168
Links broken and even googling them doesnt bring up this magical expensive system.

The one takeaway from your “review” is that a siphon bulb will make my inline filter work better whether its on a gravity filter or part of a true inline filter direct from a bladder. For around $10 i can get the siphon bulb off amazon and pair it with a sawyer filter, with any of the already modified filters systems i got. So for that idea, i thank you.

Yes! Great idea adding a siphon bulb to an existing Platypus!
Getting the system primed is usually the biggest PIA.
Which bulb did you buy?
 

stumpy waters

Junior Member
Joined
May 24, 2017
Messages
49
Imagine rolling into your campsite after hiking in, dipping a bag into the water source near camp, and by the time your shelter is set up, you've got 6-12L of clean water waiting for you.


I started reading then I got to this line and thought “I have that already”, with kit I put together for well under $100, using platypus bags, and a sawyer filter and a charcoal filter, and have been using successfully for longer than just the past few years. Works well enough I never did any dreaming about a better system.

Then I scrolled down to see how long the infomercial was, and kept scrolling, and scrolling, and scrolling... and decided nothing could be worth reading a post this long. :)
 

Moserkr

Senior Member
Joined
Feb 26, 2020
Messages
515
@FishfinderAK I havent bought one yet, but i just searched for “siphon bulb”. The one the OP uses happens to be an “enema” bulb lol, from what i saw. Didnt know it was a thing but now my wife will wonder why im looking for em on amazon hahaha. It wad the closest thing to a food safe siphon i could find. But I will definitely be adding it to my systems.
 
OP
Jake Larsen

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
Ok so this is a real question.

How is this different then the platypus system?
Other then the priming bulb i don't see how it's different.
Looks more heavy duty. Price isn't much more.
But I just can't tell how its totally different.

But I also don't use the platypus system.
There's a couple things IMO. One big thing is the total volume. The Bitterroot can handle 12-14L comfortably. Also the Frontier is a much better quality inline filter IMO. Also the versatility of the UQC to adapt into a straw, or integrate into something like the Geigerig or however else you want to use it.

Sent from my Pixel 3 using Tapatalk
 
OP
Jake Larsen

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
I started reading then I got to this line and thought “I have that already”, with kit I put together for well under $100, using platypus bags, and a sawyer filter and a charcoal filter, and have been using successfully for longer than just the past few years. Works well enough I never did any dreaming about a better system.

Then I scrolled down to see how long the infomercial was, and kept scrolling, and scrolling, and scrolling... and decided nothing could be worth reading a post this long. :)
If you've had a system like this working for you for a long time, kudos to you! I'm just trying to help people out. And yes, I tried to be very thorough with my explanation. If you've got constructive criticism or feedback on how it could be made better, that's what this website is all about. If it's not for you, move on

Sent from my Pixel 3 using Tapatalk
 
OP
Jake Larsen

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
Links broken and even googling them doesnt bring up this magical expensive system.

The one takeaway from your “review” is that a siphon bulb will make my inline filter work better whether its on a gravity filter or part of a true inline filter direct from a bladder. For around $10 i can get the siphon bulb off amazon and pair it with a sawyer filter, with any of the already modified filters systems i got. So for that idea, i thank you.
Thanks for the heads up on the broken link, got that fixed.

I'd be interested to see a list of components or modified platypus/Katydyn systems ect to match the Bitterroot in function, durability and capacity for significantly less $. I have those in my gear room also, I've been tinkering with all of them all for several years. This works way better than anything I've come up with. Jason nailed this one, that's the reason I took the time to share it.

Sent from my Pixel 3 using Tapatalk
 

Moserkr

Senior Member
Joined
Feb 26, 2020
Messages
515
@Jake Larsen Ive rebuilt multiple setups from katadyn to sawyer and more. Only thing new is the bulb but it wont be easy getting people away from a tried and true filter to some less known one. If these guys want to sell their system in pieces, that would also be effective. Id happily pay $10 for that siphon bulb so I dont have to google search for enema supplies anymore lmao.

13oz isnt anything special either. Thats heavy to me compared to direct inline filters to a bladder, or tablets/drops. Its average for a gravity filter though, and one can be built with leftover pieces from other kits or from the ground up for under $40, including a sawyer filter which is well established.
 
OP
Jake Larsen

Jake Larsen

Senior Member
Joined
Sep 11, 2017
Messages
731
Location
Bozeman, MT
@Jake Larsen Ive rebuilt multiple setups from katadyn to sawyer and more. Only thing new is the bulb but it wont be easy getting people away from a tried and true filter to some less known one. If these guys want to sell their system in pieces, that would also be effective. Id happily pay $10 for that siphon bulb so I dont have to google search for enema supplies anymore lmao.

13oz isnt anything special either. Thats heavy to me compared to direct inline filters to a bladder, or tablets/drops. Its average for a gravity filter though, and one can be built with leftover pieces from other kits or from the ground up for under $40, including a sawyer filter which is well established.
I agree with you, that for a guy who already has a bunch of money/time/extra parts into building a similar setup, it might not make sense to start over buying one of these. Add the bulb, and go to town. But for someone who's in the market with a fresh perspective, it's a unique option.

I do have to point out one thing that's a big deal (at least for the way I'm using a gravity filter). The Bitterroot can do 14L at a time. No one else has that capacity on the market. My hunting partner and I can have 3 days of water for both of us filtered and stored for 5 minutes of work. The closest I'm aware of is Katydyn with a 10L bag that has a garbage filter, no good way to route clean water into a storage bag, no way to prime the system, and still costs over $80.

Regarding the Aquamira Frontier filter, it's been around for a few years now. The specs are available on their website, as well as tons of written and video reviews. It's got a very good reputation. I've used the Sawer as well, and it's definitely a good filter too. Imo the Aquamira is a bit more versatile because of the UQC system. I think it's a better choice for this specific purpose, but to each their own.

What bag/filter/component combo are you using in order to build a similar system for $40?

Sent from my Pixel 3 using Tapatalk
 
Last edited:

stumpy waters

Junior Member
Joined
May 24, 2017
Messages
49
If you've had a system like this working for you for a long time, kudos to you! I'm just trying to help people out. And yes, I tried to be very thorough with my explanation. If you've got constructive criticism or feedback on how it could be made better, that's what this website is all about. If it's not for you, move on

Sent from my Pixel 3 using Tapatalk

LOL I’ll move on whenever I please, not at your direction.

Constructive criticism? Yeah don’t be so ridiculously long with your posts and more folks might read them.

The way you started out it wasn’t really an explanation. It sounded like a sappy love story with a plastic bag. :)
 
Top