Sawyer Gravity Setup – Bag Alternatives

[KRS]

John, Platypus will sell you one, you just have to call to get one. For some reason they don’t sell them on the website.

[Crow]

I use a 2L Platypus CleanStream dirty bag and it works great!  However, I think an upgrade to 4L would make me happier.  I just upgraded from the Sawyer Squeeze filter to the Sawyer 3-way which has built-in quick disconnect fittings and simplified my kit, with better throughput to boot.  With the Squeeze I had those screw-on adapters with a bit of hose and then quick disconnect adapters to make the whole system easy and versatile (we use Platypus bladders in our packs, and installed quick disconnects on the bladder lines, so we can refill them without removing the bladders from the packs or any chance of spillage).

It can be carried in your bag, but be careful.  It’s not like the Big Zip which has something to hold the ziplock shut.  I never had an issue when carrying it, but when I layed my pack down in my tent once I created a swimming pool, so never again.

[Crow]

I just called Cascade Designs and they said they are in the process of relocating their repairs department and as such, replacement parts are all boxed up and not currently available for sale.  They advised to call back in 2-3 weeks.

[Yoyo]

If you are using the Sawyer filter in gravity mode (as you should–the flow rate will be much faster), you don’t want to screw the filter directly onto the Platypus bag.  You want some kind of male adapter so you can attach the hose.  I used a cap that was designed as an alcohol squirt nozzle.  I wish I had something better–indeed I think Platypus or Sawyer makes such an adapter.  I recall seeing one on REI’s website.

[Crow]

Both the blue adapter sold by Sawyer (part of this kit:  http://amzn.com/B008JX0QP4), and the spare parts that come with the Platypus 2L Replacement Dirty bag (I think) – namely a clear plastic screw-on ring and blue L-shaped hose fitting that are identical to what the Hoser bladders use – will work for screwing on to a Platypus bag, and presumably many other things.  Of the two I prefer the Sawyer as it’s one piece.

I ordered this for some good hose to cut pieces from:  http://amzn.com/B00453ULP2 – the spare Platypus parts may have come with that if they didn’t come with the 2L bag – either way I ended up with them.  I actually used both the Sawyer and Platypus adapters – one with a bit of hose and a female quick disconnect – the other with a male.  I use the former when I fill up my bags with clean water, and the latter to transfer water from the bags into our pack bladders in the case that we carry extra water with us in the bags and the bladders run dry.

[Yoyo]

Kurt,

I’m really interested in this quick-disconnect rig.  I did the opposite as you–I started with the 4L Cleanstream setup for my wife and I with the open top, but now have transitioned to just a 2L Platy as a dirty bag (actually holds 2.5 L).  The reason: it’s lighter weight.  Downside is that the 2L Platy is a pain to fill.  But that just means I need to take out my pot and scoop.  This takes me maybe 2-3 extra minutes out of my entire day.  Not a big deal.  The advantage of the Platy is that you can screw on the cap and stick the whole thing need in your backpack if you needed to carry more water for longer stretches.  I wouldn’t trust the zip top in my backpack.  I just used it to haul to camp from the stream.

 

I really miss the quick disconnect feature though, and I think I’m ready to add it back and take the 2-3 gram penalty.  Regarding your quick disconnect project, can you tell me if there’s any leakage in the cap where you drilled?  I plan to do this for my Platy bag.  If you plan to get rid of the quick disconnect thingie, I’ll be happy to Paypal a few dollars to take it off your hands.  :)

[Crow]

Note that since we’re comparing parts from Platypus and Sawyer – the female quick disconnect from Sawyer is more compact, but does not have an automatic water shut-off when disconnected, so water will squirt out everywhere.  The Platypus ones are much better in this regard.

[KRS]

David,

The Evernew caps are awesome, they are beefy and don’t leak a drop with the quick connect added. I did all the drilling on my drill press so the hole is perfectly centered, this is important for the nut I used on the inside to make sure it didn’t come loose. If you send me the parts I can make them for you.

Parts:

http://www.usplastic.com/catalog/item.aspx?itemid=37282&catid=926

your Evernew cap

I will supply the nut (very hard to find)

[Yoyo]

Hi Kurt,

 

Thanks for the offer, I just might take you up on it.  I’m also thinking of splicing a quick disconnect into my drinking hose.  Normally what I do is I remove the bite valve and then shove the drinking hose onto the filter itself.

 

I was thinking of ordering this

but the part you referenced from US Plastics looks quite similar.  Do you know if the US Plastics part would work for this purpose?

Do you happen to have a scale that weighs in tenths of a gram? I’m curious to know how much the quick disconnect setup added to your cap.  Maybe you could use a nylon nut to save weight?

[Yoyo]

One more question: Does anyone know if tubing like this would work with a gravity setup?

It has a thinner ID (3/16″ instead of 1/4″) and a thinner wall as well (1/32″ vs. 1/16″).  I’m curious what the weight savings would be.  Given that the wall thickness is 1/2 of what you normally find on Platy tubing, and the overall diameter is less, it should be around 40%-50% of the weight of Platy tubing.  Am I right?  Based on my measurements, regular Platy tubing weighs around 1.15 g per inch of tubing.  With 24″ tubing, that comes in around 28 g, or 1 oz.  That would mean a 0.5 – 0.6 oz weight savings with the lighter tubing, no?

 

[Crow]

I have a tenths-of-a-gram scale…I will weigh both the Sawyer and Platypus quick disconnect components tonight if nobody else gets to it first.  The Sawyer one would be lighter as it’s smaller on the female end if you don’t need to cut off the water flow when you disconnect.

[Crow]

The medical tubing is an interesting thought.  What length of tubing is ideal for a gravity setup?  I have used pretty short pieces of tubing but maybe I should rethink that.

Does anyone know of a strong Y-adapter that will work with the Platypus or whatever other tubing?  I think it may work out better for me to have two smaller bladders in my pack, one on either side, instead of one bigger one in the center which can make fitting in gear suboptimal.

[KRS]

The tubing you guyz want is http://www.usplastic.com/catalog/item.aspx?itemid=36285&catid=799

The Clamp you want is http://www.usplastic.com/catalog/item.aspx?itemid=104025&catid=858

The valve you want for the cap is http://www.usplastic.com/catalog/item.aspx?itemid=104025&catid=858 you will have to reduce the amount of threads that it has I used a belt sander with a nut on the QC as a guide.

The nut that I found that fit the QC fittings is a lamp repair part made of nylon. it was in the drawers at my True Value Hardware store.

David the QC you found on Amazon will work but if you are ordering from US plastic just get everything from them you want 1/4″ QC

The weight of the Evernew cap is 5g the Evernew cap with the QC is 10g. The crazy thing was my Platypus 4L bag with a less beefy strap weighed less than the 2 Evernew bags with the QC caps by .2 oz’s. So it really was a wash to go to the platy bag.

[Crow]

Kurt, your tubing link points to a down jacket.

The clamp, I found I didn’t like and don’t use.  I just don’t see the purpose of it.  Why do you find it necessary?

[KRS]

Fixed new link! Why I like having the clamp is for priming the filter. I can get the water right up to the filter then screw on the filter this prevents the dreaded vapor lock you can get with a gravity filter. Also it’s nice to have the clamp in camp since I just filter water as i need it from the 4L bag.

[Crow]

Weights of quick disconnect parts:

• Male end: 2.2g
• Sawyer female: 3.7g
• Platypus female (with spring-eject and auto-shutoff): 7.0g

Note that all of the above parts, regardless of whether purchased from Sawyer or Platypus, are in fact the ones made by CPC.

As for the cap-to-hose adapters:

• Platypus cap: 4.8g
• Sawyer cap: 7.9g (5.9g without rubber O-ring)

And the filters themselves (all used, shaken out but most likely not completely dry):

• Mini: 48.2g
• Squeeze: 80.0g
• Squeeze hose adapter fittings: 12.3g
• 3-way: 105.5g

This is my current water setup:

This was my previous setup with the Squeeze (bladder not shown but same as above) – note I was using the Platypus cap adapter (exact same parts as used on the bottom of the Platypus Hoser bladders) as I only had 2 of the Sawyer ones and it had come with something else:

Here are the 3 Sawyer filters side-by-side for size comparison:

The Platypus hose fitting holds the hose on MUCH better than the Sawyer, but the loose screw-on part is annoying.  On the other hand, you could use two of the blue L-shaped fitting inserts, and carry only one of the clear screw-on parts for further weight reduction.  The Sawyer fitting almost demands a zip tie on the hose to hold it in place.

[Yoyo]

Kurt,

The tubing you linked is 3/16″ ID.  I understand that Platypus tubing is 1/4″.  Will yours work?  I prefer this this one

because it is clear and medical grade tubing.  Any reason why you recommend the silicone tubing instead?

Just to confirm, are these the quick disconnect parts from USPlastics that I need?

http://www.usplastic.com/catalog/item.aspx?itemid=37282&catid=926

http://www.usplastic.com/catalog/item.aspx?itemid=36298

 

Edit: I noticed that you recommended the clamp from US Plastics as well.  One of the primary motivations for the quick disconnect coupling is so that I can use the system as a faucet (turn it on, turn it off).  Do you think that when I disconnect the coupling as you had it set up, the filter will fall?  When I had the Platypus CleanStream 4L bag with the 90 degree disconnect elbow, pressing the disconnect button allowed the tubing to be held in place due to friction.  It was really like having a kitchen faucet in the backcountry.

Casey,

Thanks for the weights and the comparison between the filters.  Given the weights, I think I will go with the all black Sawyer.  I have just placed an order on ebay for the water bottle version.  I’m hoping it is exactly the same as my circa 2009 version that I purchased from REI.  It weighed 2.5 oz wet.

[KRS]

• The smaller silicon tubing fits better than the 1/4 silicon tubing IMO. It is food grade as well so it has no nasty flavor. It is the exact same tubing you would find on the PUR Hiker filters that where popular 5 years back. The clamp works with my rig but your set up or use might be different. I know the fittings I have after they are popped open they completely come out.

[Adam Kilpatrick]

Another option for durable water bags are the ones from Ortlieb. I’ve used mine for yonks. They are tough as. Not sure of weight (mine’s at work at the moment), would be similar to the MSR. I’ve also used Platypus and camelbak bladders extensively…I trust the Ortliebs literally with my life…so I don’t care about their increased weight.

[Crow]

I take back my previous statement (and removed it from my previous post) – the white rubber O-rings in the Sawyer fittings *is* important.  I thought it screwed on tight, but when I went to use it, it started leaking everywhere.  So you do need to keep that in place.

I also pushed bleach-water through all my filters last night, and afterwords shook them out as well as I could, and took “freshly-wet” weights, which would represent the actual weight in your pack.  The Squeeze ended up being much heavier, to the point that the 3-way ends up being lighter when you take into account the tube adapters, short pieces of tubing, and quick-disconnect adapters like I used to use. This makes sense since the Squeeze was the least recently-used last time I measured weights.  Also tested all 3 filters using the faucet adapter, and found that the 3-way definitely has the best flow rate – though I didn’t measure time to fill up a jar or something, it seemed that the Squeeze was perhaps double the rate of the mini, and the 3-way was about double the rate of the Squeeze.

Weights:

• Mini: 52.8g
• Squeeze: 93.7g
• 3-way: 109.0g

The two fittings for the squeeze (blue and grey screw in/on pieces) weigh an additional 12.3g bringing the Squeeze weight up to 106g, and then there’s the weight of quick-disconnect fittings and tubing if you want to add that functionality, which is already built-in to the 3-way.

So, the 3-way is the clear over the Squeeze winner in my opinion, and the mini is simply too problematic for me as it clogs up too fast.

[Yoyo]

Seems like the Squeeze isn’t ideal for gravity setup since you have to add the screw on adapters, which adds weight.  For myself, I have the water bottle filter on order from ebay.  My hope is that it is the old black Sawyer that I used to use (which now has been ditched due to microbial growth).  The flow rate on that one was acceptable and it has similar male fittings to the Mini.  And it weighed around 2.5 oz wet, lighter than the Squeeze.  I have some parts on order from US Plastics, too.  I’ll report back when I have the whole thing set up.  I’m combining Kurt’s ideas with other thoughts I’ve had for a while concerning an improvement of my current system, which is in something like the 4th iteration.

Last night I tested the flow rate of my Mini in gravity mode: it took about 14 min to filter 2 L of water.  Acceptable but pretty slow.  With 2 or more people I think this would be pretty worthless.

[Crow]

So what’s an ideal length of tubing above the filter for a gravity filtration setup?

[Yoyo]

That’s an excellent question.  I used to use tubing around 40″ in length.  Lately, I’ve been using tubing around 24″ in length.  I think what I will do, when I have time, is do some more scientific testing: Cut tubing to various lengths and test flow rates and graph the results.  One can then choose the best compromise between flow rate and weight.

I placed an order for 10 feet of 1/4″ ID tubing with 1/32″ walls from US Plastics.  I’m curious to see what the weight savings might be over the stock Platy tubing.

One thing that Kurt’s post reminded me of–the dreaded “vapor lock” is a huge problem for gravity filters.  My plan for my new system is to have a quick disconnect immediately above dirty input on the filter.  With the shut off valve built in, dirty water can fill the entire dirty tubing except for the 1/2″ of tubing necessary to connect the male end to the male end of the dirty input on the filter unit.

The advantage to the 3 in 1 filter (SP122) is that it appears to have a female quick disconnect on the dirty side (am I right?).  By purchasing a male end from US Plastics that has a built in shut off valve, you could fill the entire dirty tubing with dirty water, then connect it directly to your filter and voila!  There shouldn’t be any air bubbles above the filter.  The only downside I can see to the 3 in 1 filter is that you can’t suck out any air bubbles from inside the filter–or at the very least it seems like it might be more difficult due to the lack of a male barb on the clean side, as found on the SP121 black Sawyer and the Mini.  I think the quick disconnect parts on the 3 in 1 (SP122) aid in easy setup but also retain more water, which likely is resulting in the higher wet weights Casey is getting.

Anyway, I hope to make a video on all this soon and post it on my youtube channel for all to see.  I’ve been playing with gravity water setups since at least 2008 or so.  I originally was using the Frontier Pro that BPL used to sell many years ago and have migrated between Sawyer filters with different dirty bags.  I think my newest iteration will be the result of a lot of time (too much!) spent thinking about this, with the input of you guys here to help me along the way.

[Crow]

Yes, the 3-in-1 filter has a female quick disconnect fitting built into the filter housing on the dirty end, and a male quick disconnect fitting built into the housing on the clean end.  It ends up being lighter than the Squeeze with adapters and fittings to accomplish the same thing.

I’m not sure when you’d need to suck on the male end (gotta keep from laughing here) of the filter, but the quick disconnect fittings on the 3-in-1 filter have no auto shutoff so you should be able to do that easily enough.

I’d certainly love to see any video you have time to put together!

[Crow]

P.S.  Where is a male fitting with auto shut-off?

[Author]

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