Sawyer Gravity Setup – Bag Alternatives

[J-L]

I’ve been using my Sawyer filter with a gravity setup for over a year now. It’s pretty simple: I hang a water bladder up on a branch or nub, then have several feet of tubing hang down, and connect the Sawyer at the bottom. This provides a large amount of water pressure and results in a fast flow with little effort. All you have to do is hold the filter over your clean water container. It’s very effective for small groups. Here’s a photo:

The only problem is the water bladders. Whether from Sawyer or Evernew or a generic eBay brand, they only seem to last 1-2 years before needing replacement. So I am looking for more durable bladder alternatives

I was originally thinking of trying to connect my gravity setup to an MSR Dromlite. The 6L version (listed weight = 5.7oz) would be a couple ounces heavier than 3 x 2L-Sawyer bladders, but should provide a durable and easy-to-fill option that also allows for substantial water hauls and uninterrupted filtering

Then I began looking at other gravity setups which basically have tubing coming out of a large dry-bag. These setups do not seem to weigh much less than the Dromlite option and might even be heavier. A couple examples:

MSR Hyperflow bag (4L, 4.4oz): http://www.cascadedesigns.com/msr/water/accessories/hyperflow-gravity-kit/product

Katadyn Gravity Camp (6L): http://shop.katadyn.com/product/8019160?catalog_id=1&language_id=1

Another interesting option is the Sea to Summit Pack Tap, but I have no idea how you could connect tubing to it (supposedly the 8L version only weighs 4.4oz):

http://www.seatosummit.com/product/?item=Pack+Tap&o1=2&o2=2&o3=229

Any other ideas? I think the lightest option would be something like this Sea to Summit silnylon bucket (10L and 1oz) with a tubing connection attached to the bottom; however, I have not found such a product

http://www.seatosummit.com/product/?item=Ultra-Sil+Folding+Bucket+&o1=0&o2=0&o3=360

[Ken Thompson]

How/where do the Evernew bags fail?

[Lester Moore]

At around one ounce each and moderately priced, one could simply replace their LW water bladder every year or two and save several ounces over a heavier bladder.

[J-L]

At around one ounce each and moderately priced, one could simply replace their LW water bladder every year or two and save several ounces over a heavier bladder.

Yes, that’s what I’ve been doing and maybe that’s the best option. But I would like to learn about other options to avoid continuing doing this. A silnylon water bag with a hose attached to the bottom, for instance, could potentially be both lighter and more durable (if it existed)

The Evernew bladders definitely last the longest. I’ve lost one due to a random crack that appeared in the middle of the bladder (possibly due to rolling up many times). But usually a small hole will appear somewhere near the top. Here’s one Evernew bladder that will probably fail in 6 months to a year:

[Yoyo]

I used to use the CleanStream Gravity dirty bags from Platypus.  I don’t know if they still make these or not.  What I loved about the system is the quick-disconnect feature which acted as a kitchen faucet to regulate flow.  If I recall correctly, the dirty bag (4L) weighed around 2 oz.  I recently switched to a regular 2L Platy bag to save weight (around 1 oz?).  The downside to regular Platy bags is that they are hard to fill due to the narrow mouth (same for Sawyer bags).  I use my cookpot to fill from a stream, takes an extra minute or so.

[Yoyo]

To add to the above, I’ve never had a Platypus bag fail on me.  Not once.

[J-L]

That’s interesting, David. I have not used Platypus bladders because they used to not screw onto the Sawyer correctly. Platypus sells replacement bags for their 4L gravity system. Any idea if those bags are similar to yours?

http://www.cascadedesigns.com/platypus/filtration/gravityworks-40l-filter/product

[Jay L]

Ive been using dry bag as my upper reservoir for a couple of years.  I usually trek with a group so I wanted a fairly large capacity system.

• 10L Outdoor Products dry bag (the yellow one in the Walmart 3-pack)
• A “1/4 inch adapter for hanging tube waterer” from qcsupply.com for attaching the hose to the dry bag  http://www.qcsupply.com/quarter-inch-adapter-hanging-tube-waterer.html
• A Boli 10L collapsible water carrier for the output reservoir

I have an Amazon list set up so I can find the parts again when I want them:  https://amzn.com/w/1JBISM2JI9X27

One caution:  First time I used it I rolled and clipped the top and hung it by the clip – the clip broke instantly.  Now I do not roll the dry bag closed, but larks-head a cord around the neck just below the stiff lip.

 

[Nick D]

I use the older MSR Autoflow for groups and really do like the durability of the MSR bag. It holds 4L+ and has two straps for hauling/hanging. The huge mouth is a one scoop fill. I also like the internal mesh pre-filter and quick disconnect. I pulled the rubber ‘nubs’ off the actual filter and ditched the nalgene connector. I think mine is around 9oz.

I see they’ve updated the system and it’s lighter around 10.5oz. Remove the items mentioned above and you’d probably get down to 8oz. Hard to beat for such a bomber system.

http://www.rei.com/product/892168/msr-autoflow-gravity-water-filter?cm_mmc=aff_AL-_-34947-_-46631-_-NA&avad=46631_faa203dd&CA_6C15C=120217890000021193

 

 

[Alexander S]

Does anyone know which kind of tubing adapter I need to screw into the Evernew bag?

[D S]

Same as above – Where to get adapter for tube to Evernew Bag?

[J-L]

Jay, that 1/4” adapter for hanging tube waterer looks perfect. Is it as simple as cutting a small hole in the bottom of your dry bag and screwing the adapter in? Any leakage or durability issues?

Glad to know the MSR version can get that light. Could be another good option

For connecting the tube to an Evernew bladder, get the Sawyer Inline Hydration Adapters:

https://sawyer.com/products/sawyer-inline-hydration-pack-adapters/

The blue one screws onto the Evernew and the gray one screws onto the back of the Sawyer. Connect with a tube in between. I use some tubing I bought from McMaster-Carr: Beverage Clear Tygon PVC Tubing 1/4″ ID, 5/16″ OD, 1/32″ Wall Thickness. Much lighter than normal hydration tubing like from Camelbak

 

[Alexander S]

Thanks John.

[JCH]

My setup is similar to the one mentioned by @dgposton.  I use a Platy Big Zip reservoir that was sitting around unused for the dirty bag.  I really like the hose quick disconnect and the big zip-lock opening for filling quickly. The convenience is worth the extra ounce to me.

[Jay L]

Jay, that 1/4” adapter for hanging tube waterer looks perfect. Is it as simple as cutting a small hole in the bottom of your dry bag and screwing the adapter in? Any leakage or durability issues?

I picked a socket the right size, heated it with a torch and melted the hole in the dry bag.  Yes, just screw the adapter together.  It comes with a metal washer and a rubber washer – I put the metal washer outside of the bag and the rubber washer inside.

There is a small amount of leakage, both at the adapter and through the bag itself.  The amount is about what you would see from condensation with very cold water on a hot day.

The system has been very durable – I made three of these filter setups for my Scout Troop.  Each filter has been used for 2 one-week trips when the Scouts did all of the filtering and backflushing. No issues other than the broken roll-top buckle mentioned above.

 

 

[J-L]

I ordered a couple of the 1/4” adapters. I plan on trying out the idea with a silnylon water bag I have.

[Kenneth Keating]

Um.  I like the looks of the MSR Hyperflow bag, but the price is steep at $75.  I wonder if you could use a $28  Zpacks medium dry bag with the tubing adapter.   For 5.6 liters at 0.85 oz, it’d be light.  I imagine it may not be completely leak proof, but what would be the harm if it leaked very slowly? You’d have to add some grommets to attach the hanging cord , but that’s easy to do.

K

[JCH]

I imagine it may not be completely leak proof, but what would be the harm if it leaked very slowly?

Having dirty/contaminated water dribbling all over your clean water bag and filter?

Back when I was using tablets only I had a rather nasty 2 days in the backcountry as a result of there remaining some untreated water on the threads of the bottle…where I put my mouth to drink. Learned once and for all to keep the OUTSIDE of the clean side of the system clean as well.

[Matthew / BPL]

I’ve always been concerned about any leakage using a gravity filter so I am careful to place the tubing so that there is a U-shaped trap before the water gets to the bottle I am filling.

[KRS]

I use a 4L Platypus dirty bag that is part of the Clearstream kit. I bought it from Platy directly for $25. This is my in camp setup, notice the shower attachment that is great. While hiking I screw the squeeze on a smart water bottle filled with dirty water and keep in a side pocket. I fill a clean smartwater bottle and carry up front on my shoulder strap. I designed this set up so the filter could be switched easily between setups. The Platypus replaced my older system. My old setup I drilled a hole in the cap of an Evernew cap and added a valved quick connect. I loved this system but I wanted more water in camp and an easier way if filling the bladder. Also the platypus lets the dirt settle to the bottom helping to keep the filter clean longer.

[JCH]

Kurt,

Could you tell us what the 4L Dirty bladder weighs by itself?

[KRS]

John on my scale it is 3.1 oz but thats with the heavy strap that comes with it. I believe the strap is close to .8 oz but I can’t remove it without cutting it off.

 

[J-L]

Does the 4L Platy bladder use the same kind of material as a normal, smaller Platy bladder? Would it be suitable (leakproof enough) for hauling water in a pack?

[KRS]

It has a more rubbery feel than the normal bottles. So I’m going to say no, it is not the same material. As per hauling in a pack you could but it could pop open. I actually found the Big Zip’s blue clip fits on mine perfect to prevent that. I have not brought the clip on a trip as of yet because I have plenty of water along the trails here.

[JCH]

Well shoot…my repurposed Big Zip weighs 3.5 oz and at only 2L I often have to fill it twice. Looks like I need to see if Platypus will sell me just the 4L dirty bag.

[Author]

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