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Eric Brigman
(engine386) - F

Locale: Central Florida
2 gram back flush for sawyer squeeze on 06/25/2013 09:33:23 MDT Print View

After having my filter clog up on me in the middle of a backpacking trip, I was determined to find a better solution than the syringe. This is what I've come up with. (FYI, I have the older squeeze without the nipple on the outlet side).

I've always used the flip-top sports cap from a smartwater bottle, as I don't have to worry about using the lid. This makes up half of the the back flush.
For the other half, you just need one more smart water sports cap. Tear of the flip-cap and 'pop out' the blue center spout.... That's it, your done. When connected as in the photos, it snaps together to make a secure fit back flush with.Filter as normally usedSet up for a back flushLocked in placeOnly additional piece taken

All for the cost of a bottle of water.
I now use a evernew bag to drink from, but it also worked when I used to use a smart water bottle.

John Arwood
(johnlarwood)

Locale: Mountians of East Tennessee
2 gram back flush for sawyer squeeze on 06/25/2013 10:27:46 MDT Print View

Thanks Eric. This is a nice light setup that uses already on hand materials. Way to go!

Ian B.
(IDBLOOM) - MLife

Locale: PNW
Well done sir on 06/25/2013 10:31:52 MDT Print View

Just ordered my Sawyer yesterday. I was struggling with whether or not to bring the syringe but at 2grams this is a no brainer.

Eric Brigman
(engine386) - F

Locale: Central Florida
Nipple on Sawyer on 06/25/2013 12:17:52 MDT Print View

I believe if you have a newer sawyer squeeze with the nipple on it, the flip-top cap tip should fit/snap into place onto the nipple.

stuart thomas
(linuxfree) - M
Filter on 06/26/2013 04:43:48 MDT Print View

Nicely done!

Drew Jay
(drewjh) - F

Locale: Central Coast
Bravo on 06/26/2013 20:40:10 MDT Print View

This works great. I added some teflon tape to the threads on my Sawyer and Evernew bladder as it was leaking a bit from the threads, not a big deal.

Edited by drewjh on 06/28/2013 21:17:06 MDT.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: A parallel BackFlush thread - on 06/26/2013 22:03:59 MDT Print View

A Tornado Connection

Drew Jay
(drewjh) - F

Locale: Central Coast
New Squeeze on 06/27/2013 05:28:17 MDT Print View

I tried this on the new-style Squeeze as well. It works even better! The tip of the SmartWater cap snaps onto the nipple very tightly.

J C
(Joomy) - M
Awesome. on 06/27/2013 21:56:32 MDT Print View

I'm sold!

Drew Jay
(drewjh) - F

Locale: Central Coast
More info on 06/27/2013 23:12:56 MDT Print View

I was asked for explanation, so - screw the Smartwater cap (unmodified) onto an Evernew or Sawyer bladder after adding some teflon tape to the bladder threads. Then with the cap removed from the Sawyer Squeeze, push the tip of the Smartwater cap onto the Sawyer Squeeze nipple. It snaps tightly into place and you can really put some pressure through the filter with a full bag.

Jeff McWilliams
(jjmcwill) - M

Locale: Midwest
Teflon tape on threads on 06/28/2013 07:39:06 MDT Print View

Drew,

Won't you need to carry a roll of teflon tape with you on the trail? That stuff wears out pretty quickly if you have to remove the cap to fill the bladder, then replace it to drink from, or back flush the Squeeze.

Drew Jay
(drewjh) - F

Locale: Central Coast
Teflon Tape on 06/28/2013 08:43:43 MDT Print View

I put about 8 wraps on mine and it seems to be holding up fine. You can backflush effectively without the tape, it just leaks a bit under pressure.

KEN LARSON
(KENLARSON) - MLife

Locale: Western Michigan
***Clarification & NEW TRICK for Original SAWYER Filters to use in FIELD BACKFLUSHING*** on 06/28/2013 09:35:55 MDT Print View

Drew....I am still confused as to the process you have tried to described.

Being a visual learner a picture as I previously indicated would be of help to me to understand your method as I was unaware SAWYER made an update to the "push-pull" caps. I have one of the original SAWYER Squeeze Filters as Eric has and the "push-pull" nipple on our filter is larger than the Smartwater cap hole to fit and seat into.

When you mention Smartwater cap (unmodified) am I to assume you have not removed/pushed the BLUE spout out of the Smartwater cap?.........YES

Smartwater Bottle Cap

Have included pictures of various item associated with this thread that might be of interest for clarification.

Push-Pull Cap

Original Sawyer Squeeze Filter owners, you can FORCE the original "push-pull" nipple INTO an Evernew bag spout with some effort and likewise black flush. This set up facilitated backflushing as good as Eric's Method and SAWYER Syringe Method that I have used in the past. How it works in the FIELD is unknown on filter needing maintenance is unknown.

Direct Insertion Push-Pull Cap

Smartwater Bottle Cap Back Flush Set Up

If you get a change I would appreciate a picture of your set up......Thanks

kenlarson40@chartermi.net

Drew Jay
(drewjh) - F

Locale: Central Coast
More on 06/28/2013 12:05:20 MDT Print View

Yes by intact I mean the blue spout is still in place on the SmartWater cap. If you remove the white push/pull cap from the (new model) Sawyer Squeeze there is a molded nipple (outlet) where you would normally fit the syringe. Just push the blue spout on the Smart water cap over that and it will snap into place. I will try and take a pic tonight.

Edited by drewjh on 06/28/2013 12:26:06 MDT.

Ken Thompson
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: 2 gram back flush for sawyer squeeze on 06/28/2013 19:38:05 MDT Print View

I've tried this a few times now. The inside diameter of the blue tip fits over the nipple on the filter very snugly. It also bottoms out. I have no leaks using it this way.

Thanks again.

Edited by kthompson on 06/28/2013 19:39:52 MDT.

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: 2 gram back flush for sawyer squeeze on 06/28/2013 19:54:17 MDT Print View

Thanks for sharing this. I just tried it out at home and it works great. I've got a newer model Sawyer Squeeze filter and, as others have posted, the blue tip of the Smartwater cap fits over the nipple like it's made for it.

Drew Jay
(drewjh) - F

Locale: Central Coast
Pics on 06/28/2013 20:57:51 MDT Print View

So a quick pictorial:

1) Replace the white push/pull cap on the new style Sawyer Squeeze with an unmodified SmartWater cap.

SmartWater backflush p1

2) Remove the cap from the Squeeze, screw it onto your bottle or bladder, and then push the blue spout over the nipple outlet on the Squeeze until it bottoms out. Done!

SmartWater backflush p2


Also, when testing this method a second time on the new Squeeze, I removed the teflon tape from the Evernew threads and there were no leaks. I'm not sure why the difference, perhaps I cinched the lid more, or the water pressure was less. But in any event, teflon tape isn't needed for the above method.

Edited by drewjh on 06/28/2013 21:19:50 MDT.

Daryl Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Right Bottle? on 06/28/2013 21:34:34 MDT Print View

Is this the type of bottle we are talking about here?

here

Richard Cullip
(RichardCullip) - M

Locale: San Diego County
Re: Right Bottle? on 06/28/2013 21:52:47 MDT Print View

Looks like the right one. I picked up a single bottle at a local Target. Just get the one with the flip-top lid and the blue nipple.

Harald Hope
(hhope) - M

Locale: East Bay
enough pressure on 06/29/2013 12:11:00 MDT Print View

I don't believe this bag backflush method provides enough pressure to backflush and clear out the entire diameter of tubules, the syringe provided provides a huge amount more pressure, not sure if I'd recommend or use this idea, and I'm somewhat surprised nobody has mentioned this problem in this thread, you may end up creating the center channel with clogged outer channels that sawyer warns about. There's apparently a fair number of reports of filter slowdown over time, one has to wonder if methods like this are not partially to blame.

If you use an adapter and a short piece of hose and a syringe with a tip that fits into the hose, you can get far far higher pressure for backflush, simple physics, force per square cm, plunger has more force, and that's brought down the small opening.

while appealing to get rid of the syringe, I would say that this is probably not the way to do it. On the bright side, I've heard that sawyers can now be bought at walmart for $36 though of course I don't advocate buying from that place, you can probably find it online for that price too, so ruining a few filters over time isn't really going to be break the bank.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: enough pressure on 06/29/2013 13:04:49 MDT Print View

Out of the box, and after priming, my PointOne had an initial flow rate of about 1 liter per minute.

I acquired significant degradation from microscopic algae in the BWAC.

After field backflushing with a bladder it had a flow rate of about 1 liter per minute.

When I got home I backflushed with house pressure and ran a bleach solution though it.

I checked again and I had a 1 liter per minute flow rate.

It's an easy thing to check.



And a leaning on a Platy provided enough pressure to get the job done, in this case.

Edited by greg23 on 06/29/2013 19:55:52 MDT.

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: enough pressure on 06/29/2013 13:54:51 MDT Print View

"If you use an adapter and a short piece of hose and a syringe with a tip that fits into the hose, you can get far far higher pressure for backflush, simple physics, force per square cm, plunger has more force, and that's brought down the small opening."

That is incorrect.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: enough pressure on 06/29/2013 14:29:48 MDT Print View

nm

Edited by greg23 on 06/29/2013 14:31:14 MDT.

Harald Hope
(hhope) - M

Locale: East Bay
That is incorrect. on 06/29/2013 18:01:10 MDT Print View

Enlighten me please. So you're saying that if I hang a bag of air over my bike tire I can get up to 90psi? No more need for an awkward pump with a cylinder and a plunger? Awesome. I'll have to try that next time I get a flat, lol. If you're going to say something is 'wrong', at least make an effort to explain why it's wrong, particularly when it makes little sense to say so. Not saying you're not right, but you have said nothing at all beyond typing a few words, that's not meaningful. As Ricky said in the old Lucy show, "'splain, Lucy".

The other comment above however is more to the point, one can measure these things roughly, assuming you're using actual timers and actually measured quantities so that 3% degradations aren't missed, etc. So if you use a measured start quantity, and a real timer, and keep logs, avoiding 'about the same' type measurements, one certainly could make some good data points.

I'll look out for that in the future, though I won't test on my own filter. It's a good thing to track though.

Edited by hhope on 06/29/2013 18:04:22 MDT.

Dowser Tom
(DaFireMedic) - M

Locale: Southern California
It should still work on 06/29/2013 21:18:31 MDT Print View

Harold, you very well may be right. Sawyer recommends a strong backflush. But I think the cap method is still a viable way of field backflushing. Most of the reports of the Sawyer filters slowing to a crawl (my inline did this) are when the filter dries out in storage, not usually on a hike. If you need to backflush it to remove particulates that have accumulated during a hike, the cap method should provide enough pressure for this. Once flowing well, the filter generally does so for the duration of the hike unless it has a chance to dry out over several days. Once at home after the hike, the filter can be thoroughly backflushed with high pressure.

I'm just throwing out thoughts based on my experiences with the filters and as usual, I could be wrong. But I do think the cap method would do the job on a hike.

FWIW: The Squeeze filters are $29 right now with a single 32 oz bladder at Walmart. I couldn't find it cheaper online and I picked one up.

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: That is incorrect. on 06/29/2013 22:59:43 MDT Print View

Hi Harold. I hate to read threads that start off with someone being helpful and then degenerate into some other people arguing about some mildly related topic, so I didn't want to contribute to that effect, but I guess I've gone too far already. I took your statement to mean that you claim that adding a piece of hose will increase the pressure to the filter. Now that I've had some much needed sleep - it still reads that way to me. If that is indeed the claim, it is incorrect. The tubing will not increase the pressure. Actually it would only decrease the pressure output as a result of viscous losses.

As for supporting claims - you first :) I don't see any support for your claim that sufficiently high pressure cannot be generated with a bag - only postulations, no?

And for your bag of air, if you take a probabilistic view of the universe, it could indeed spontaneously inflate your bicycle tire, it is just exceedingly unlikely to happen when you want. Or ever. But statistically possible. (I offer no support of this claim, and admit I'm out of my area of expertise here.)

Kevin Gurney
(kwgurney) - M

Locale: SF Bay Area
Re: enough pressure on 06/29/2013 23:44:28 MDT Print View

What a timely topic! I just got a new Sawyer Squeeze and have used it one night in the field. I've been trying to decide if the large syringe needs to go in my repair kit bag in the field, or if I can risk leaving it at home for shorter trips. And then this space saving suggestion comes along. I love these forums...

But let's assume that this water-bag-to-Smartwater-top method actually does produce equal or more pressure than the syringe. I would be concerned that the bag - especially the Sawyer-provided bag - would be more likely to burst when backwashing a particularly clogged filter. I have more faith in the syringe's ability to take ("make", really) the pressure. Any thoughts on or experience with this? The last thing I would want is to have no way to backwash the filter in the field if that's something I think is going to need to be done.

And to settle the bet about which is mightier, the syringe or the Smartwater, is altitude is a proxy for pressure? It's been a long time since high school physics, but if I can squirt a stream of water into the air using two different mechanisms, all things being equal the mechanism that makes the stream go higher is producing more pressure. If true, this should be a very simple - and fun! - experiment to conduct.

Thoughts on this, anyone?

Dowser Tom
(DaFireMedic) - M

Locale: Southern California
Re: Re: enough pressure on 06/30/2013 09:31:06 MDT Print View

I've had my Sawyer inline for over a year and probably 400 or so miles of hiking with it. Its very unlikely that you would need to backflush it on shorter trips. Even with longer trips, backflushing is not something that you often need to do. We used mine for 3 people on the JMT last year over 18 days and didn't backflush during the hike at all. If for some reason the filter got so clogged that I needed to backflush but couldn't, I always carry a few wrapped purification tablets for emergencys. But I doubt that that will happen.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: enough pressure on 06/30/2013 10:45:03 MDT Print View

I killed a HikerPro over the course of 4 days on the CDT in Colorado. Water sources were marginal, but drinking was not optional.

I killed a Hiker Pro in about 2 weeks in the BWCA. BWCA has a microscopic algae that is notorious for this. On our last trip there I took a PointOne and killed it in about 10 days. Maybe got 75 liters out of it. So I back-flushed and continued using it.

That's why I now take a filter I can back-flush.

I'm glad you've had good luck and sad I've had bad luck.

But I no longer "...doubt that that will happen"

Daryl Daryl
(lyrad1) - MLife

Locale: Pacific Northwest, USA, Earth
Re: Re: Re: Re: enough pressure on 06/30/2013 11:07:10 MDT Print View

The flow rate of my Sawyer reduced significantly after 4 days use in the Lost Creek Wilderness of Colorado last week. Our hiking partners had a new Sawyer and did not experience flow reduction.

Water was clear but my wife stirred up a bit of sediment on one or two fillings. I have a piece of mesh in the inlet end of the filter and did not see anything retained by it.

In-the-field backflush capability is desirable to me. I'm with Greg.

Edited by lyrad1 on 06/30/2013 15:38:53 MDT.

Harald Hope
(hhope) - M

Locale: East Bay
clarification on 06/30/2013 11:26:40 MDT Print View

Stephen Parks, it can hardly be called 'off topic' to note that a method may in fact be incorrect, although alluring. So this is in fact strictly ontopic, exceedingly so, the topic being backflushing a sawyer squeeze.

If I wasn't clear, the reason I use a tube is not to increase pressure, but to make mating the syringe tip to the sawyer work way better, no leaks or misses. Trying to jam the one they provide against the hard plastic does sort of work but it's a pain. Since I already use the clean end adapter with a hose to get the water into the clean bottle, this is zero extra weight. You can also suck the water out of the sawyer before packing it up, the benefits are significant.

I realized after posting this that this question can be fairly trivially tested. With a 2oz syringe, ideally not with the catheter tip that sawyer provides, but with the longer nozzle that lets you insert it into a soft tube firmly, you can squeeze out 2 oz of water in about 1 second, give or take. Hard to time it exactly. This yields of a flow rate of roughly 120 oz per minute, but a flow rate that starts instantly, no buildup. Now we have a standard to judge against. That's 7.5 pints, or roughly 4 quarts a minute. The thing that sawyer specifically warns against is inadequate pressure forming a center channel after which you will never achieve a full clearing out of the sawyer because the water will always then follow the path of least resistance after that point. I believe that to achieve this 1 or 2 second flow rate with a platy type bag will yield a popped bag in not too long, but it's easy to test empirically so there's no need to speculate, how hard to squeeze a bag to get this burst. Remember, you don't want to build up to this rate, you want it instant to avoid forming the center channel issue.

If it takes 2 seconds to empty the syringe, then you have a flow rate of 2 quarts per minute. I'd have to time it to see what it actually takes.

The syringe, because it is a pump, which you can apply focused force on via the plunger, because you squeeze it between your thumb and fingers, using leverage, allows you to achieve this pressure/flow rate in a consistent manner, every time.

So all alternate methods can be easily tested, simply do whatever you're going to do for between 1 and 2 seconds, measure the flow out with a measuring device accurate enough to measure ounces, and there you have it. The flow rate was either in the recommended range or it was not. If you get this 2 oz in about 1, 1.5 seconds (that's counting at normal speaking speed, one one thousand) then you do in fact have an awesome 2 gram backflushing system, if it is far under that, you do not.

However, at $29 for a sawyer squeeze filter, which for those of us using hiker pros remember, is I believe less than a 200 gallon rated, non backflushable replacement filter costs, this is not a really major problem.

My apologies to any violations of physics, which I am trying to correct by noting very simple empirical facts of actual flow rates, which are measurable, and require no speculation.

So give it a try, attach devices, start backflush, into accurate measuring device, note measurement of liquid after 1 second, then 2 seconds. This test takes a few minutes to carry out.

[added]holding the sawyer and and squeezing the syringe with one hand, it took about 1.25 seconds to get the water through, 2 oz. If I put the sawyer on the ground and held the syringe in two hands, I could do it in 1 second easily. So that's actual data point 1 for those interested in such things. lol, what we do for the sake of science....

a long nozzle 2oz / 60ml weighs 36 grams roughly.

As a side note, I'd been considering the use of smaller syringes to get more compact but this discussion has finally convinced me it's a bad idea to try to save weight that way, alluring as it is re size and weight and overall compactness. From now on I will consider the weight of the sawyer to include the syringe.



I'm going to update those postings where I suggested using smaller syringes and remove that advice, I simply had not considered flow rates over time adequately, so this thread was quite useful, as were the comments of an engineer on that blog posting who also pointed to flow rates (the tubules apparently hold roughly 1/2 oz of water in volume).

When I tested using a bag for backflush, these were my results:

I did, by the way, try using two screw on ends with hoses, to try to use a bladder bag to backflush, but I couldn’t generate enough pressure, and it felt like I’d probably end up bursting the bag over time if I tried it, and it really didn’t get much more than a dribble when backflushing.

Edited by hhope on 06/30/2013 12:31:41 MDT.

Drew Jay
(drewjh) - F

Locale: Central Coast
Actual flow rates on 06/30/2013 17:50:57 MDT Print View

I just tested this using the new style Squeeze with SmartWater nozzle fit over the Sawyer nipple. I could easily backflush 60cc of water through the filter in 3.5 seconds. There was no delay, and it did not take inordinate pressure on the bag. The syringe took 2.8-2.9 seconds to push the same 60 cc's of water. Yes the syringe flows more, but not much more.

In summary, the SmartWater setup is in my opinion quite adequate for field use and I am not the least bit worried about overstressing the bag. After all you are likely to backflush maybe once a trip.

Edited by drewjh on 06/30/2013 17:52:20 MDT.

Dowser Tom
(DaFireMedic) - M

Locale: Southern California
I doubt that will happen on 07/01/2013 04:22:52 MDT Print View

Greg & Daryl,
Its good that you recognize the need to be able to backflush on a trip. When I said "I doubt that that will happen", I was referring to a situation where I would have to turn to my back up chemical treatment because I was unable to backflush the filter. Im confident that I will be able to accomplish it even without the syringe by using the method described in this thread. I never implied that I would not encounter a situation where backflushing would be necessary. I already have.

Stephen Parks
(sdparks) - M

Locale: Southwest
Re: clarification on 07/01/2013 07:59:00 MDT Print View

You have me picturing a syringe as pogo-stick for maximum output. Maybe a trekking pole attachment is needed for the long upright section.

Kathleen Whalen-Burns
(rosierabbit) - M

Locale: Pacific Northwest
2 gram back flush for sawyer squeeze on 07/08/2013 14:37:03 MDT Print View

Eric - thanks a bunch for this great idea. Today I was finally in a store that sells SmartWater bottles with the fliptop lid. I attached the lid to my Evernew, and the blue part fits nicely into the Sawyer Squeeze and squirts through just fine. I must have a different model than you, because I didn't need the second lid to attach to the Sawyer itself. Instead of carrying a bulky, 1.17 oz syringe, I can now carry the tiny .12 oz cap. Thanks again!

Paul Andronico
(Jakesandwich) - M

Locale: S.F. Bay Area
Thanks! on 07/13/2013 19:04:44 MDT Print View

Thanks Eric and Drew. I replaced the original, .20 ounce drink cap/cover from the Sawyer Squeeze with the .18 ounce Smart Water bottle drink cap/cover. So the replacement is actually lighter than the original, and I can leave the bulky syringe at home. Fantastic!