Companion forum thread to:

A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods

"Note that the in-line filters can be easily back-flushed, but not the squeeze bottles (without some tricks)."


Please elaborate further. How does one back-flush a squeeze bottle filter successfully?

Inquiring minds want to know.

Instead of squeezing water out, you blow backwards through it, and then squeeze again?

I have used a Bota of Boulder squeeze bottle filter exclusively for over a decade now; however, the water quality in Montana and the PNW is such that it probably doesn't need any filtering anyway...before I got the Bota I went 50 years without filtering and all to no ill effects. Unfortunately, the company seems to have gone by the wayside, at least I'm unable to find their replacement filters anymore. Fortunately Aquamira and Eddie Bauer both offer replacement filters that will substitute. When I can no longer find replacements then it will be time to upgrade to the Sawyer...I'm truly impressed by your unofficial review of their products. Thanks for the this sterling series!

>Bob

Assuming that's a serious question, you can backflush using Sawyer's syringe, or, from another thread here on BPL, you can use a Tornado Tube and a clean bag to force the water back through. You need to cut the Tornado Tube down a little, but it's very easy to do.

@Kent:

I'm quite serious. The squeeze bottle filters - even those from Sawyer - do not come with a syringe. The author suggests that they can be backflushed successfully, but with difficulty. I want to know how to do so.

Edited by wandering_bob on 08/22/2012 18:40:04 MDT.

Hey Bob,

I bought one Saywer several months ago (March?) and another for my wife in early July. Both came packaged with an assorted 3-pack of squeeze bags and the back-flushing syringe so I thought all are delivered that way.

Here are the instructions from a Sawyer bag: http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=65864

The syringes don't have any special back-flushing seal, you just firmly hold the plastic syringe to the plastic filter body and, quickly/forcefully run the plunger.

As for the Tornado Tube, sorry, I don't have the URL for the BPL thread, but here is one for the tube itself: http://www.amazon.com/Tornado-Tube-Tubes/dp/B0006Z8YBQ or something very similar.

Here is some of the relevant text of the BPL thread:

...since both the clean water bag and the filter are male-threaded, use this to connect for back flushing.

...I found you need to modify it by cutting (I used a bandsaw) about 1/4 inch off each end this allows [Sawyer and Evernew bags] and other standard drinking bottles to seat into the threads.

The Tornado Tube isn't hard/dense and I was easily able to cut it by hand (don't ask :-) ) using the blade from my recip saw.

I have used both back-flushing methods; they both work and are easy to do.

Hope this helps.

Edited by kent on 08/22/2012 19:29:23 MDT.

I have started using the sawer filter, at 2.5 oz dry. This has good flow, light weight, instant clean water, therefore I carry a little less. I feel the traditional pump filters are obsolete. I had been using Aqua Mira but after reading articles on the subject of water treatment I feel this Sawyer filter is better with only a few more grams of weight. I carry the 2 liter sawyer squeeze bottle,1 oz, for dirty water and additional water capacity as needed as well as extra water around camp. These bottles are not as robust as a platypus but with care will last a long time. you may want to get a package of spare bottles to keep in your bounce box. On trail I use only a 1 liter platypus with a drink hose kit. I purchased the Sawyer inline hose kit and use automotive vacuumn line caps to plug the inlet and outlet hose adapters. These work as effective plugs for the filter unit. When time to back wash I pull off the bite valve from the drink tube, connect it to the inlet of the Sawyer filter, remove the inlet plug, and squeeze the clean water platypus to back flush the filter. I use the filter only on questionable water so it goes a long time without back flushing.

I thought i was being pretty gentle with my Sawyer 32oz bag and the top seam started leaking in under 2 weeks on my LT trip. I just got a 1.5L Evernew bottle/bag 1.27oz and should be a lot more reliable.

mine also came with the Syringe for backflushing.

Bob, mine also came with the syringe. Are you sure yours wasn't omitted from the box due to a packing error?

Edited by hikinggranny on 08/23/2012 00:39:35 MDT.

I have heard that hollow fiber is fragil, if it freezes it is toast, if it is dropped it is toast. Any info on that?

Definitely avoid freezing.

What Bob is talking about is the 4-way bottle, not the Squeeze. The bottle (which I am squeezing water from in the picture) comes with a faucet adapter for backflushing at home. It does not come with any way to backflush in the field.

I can't answer for Roger, but the only way I can think of would be to rig a gravity bag, but that defeats the whole point of taking the bottle in the first place.

Avoid freezing means another thing in the sleepingbag during some of the year. Will the filter be dry enough for that? The aquapure traveler or inline seems interesting! They take away chemicals as well which is nice when hiking in places where the rivers have passet farmlands and cities. I have not found any info on if they can handle freezing. Any other opinion on the aquapure?

Water will continue to seep out of the cartridge, so seal it in a plastic bag. Just keeping it in the shelter is enough protection for a few degrees below freezing, but it's best to keep it in the sleeping bag below that.

Ceramic and hollow-fiber media must not freeze--pleated media don't seem affected as long at the filter chamber is drained.

Cheers,

Rick

Jeffrey,

I have been using the same 1st Generation "black" Sawyer inline filter since 2007 without any problems.

I use it as a gravity filter in camp, I have used it as a staw, and as a squeeze bag with Platypus bags on the JMT for 15 days last year, I have hooked it up to my faucet and blasted the water full pressure to backflush at home, run dilluted bleach through it to clean it out at home, and I have backflushed it in the field by squeezing clean water from the clean water catch bag in my squeeze bag and gravity filter setups....I have even backflushed it while using it as a straw by forcing the water filtered water in my mouth back through the filter.

My filter is still going strong and filters just as good as the first time I used it.

I have a detailed review in the user section here with photos of the inside of the filter to show the hollow fibers (newer ones are sealed so you can not poke around inside to accidentally damage them) and details how I have used it under less than idea conditions.

Yes, freezing is the one thing that can kill this filter, just as it can with any other sort of filter.

I suck the water out of the filter before storing to keep it as dry as possible.

I will then wrap my filter with a small hand cloth that I use like an all purpose wash cloth/bandana and then sleep with it in my bivy bag to keep it from freezing- easy.

The only other way to destroy it is if you manage to break the plastic housing that surrounds the hollow fibers or to snap off one of the inputs or outputs for the inline system, which I had a friend do. (Note: my friends is extremely rough with his gear and is the only guy I know who went light weight and then back to traditional because he was just to hard on lightweight gear).

Great to see the review here and that the Sawyer filter gets the attention that I think it deserves.

Hope there will be an additional review/write up on the Saywer here highlighting useage and tips to effectively use it.

Note: Playtpus bags do not thread well to the Sawyer Squeeze filter and requires modification to seat properly. Better off getting Evernew water bags that use a conventional threading.

Lastly, dropping the filter....I have not dropped mine all that much, but I can tell you that the casing on it is pretty tough. Mine has very visable nicks, scrapes, abrassions, etc...and is completely fine. It is not eggshell thin. I doubt that I could crush it with both hands if I tried to. Then again, I do have T-Rex chicken wings for arms. :)

-Tony

Edited by Valshar on 08/23/2012 16:49:46 MDT.

What a great series of articles. The explanation of the new technology (hollow fiber) is worth the cost of my subscription alone. Thanks to Roger, Will, Rick, and Ray (did I miss anyone?) for working on this. SO much better information than anything else out there.

HJ

P.S. The photo of the mad scientist at work ;) made the article all the more believable. lol.

Oh, I just bought a Sawyer Squeeze filter. I'm glad it makes my old Pur Hiker filter obsolete because that filter was big and heavy and, in any case, it stopped working 2 months ago on a backpacking trip in spite of the installation of a costly new filter element. Into the trash bin with you! I was a little nervous about the Sawyer filter's efficacy because of the small size, but now Rodger has arrived like a knight in shining armor to slake my doubt about the comparatively minuscule Sawyer. Thanks Rodger--and Sawyer too!

Any chance the author or someone else could comment on the www.bwtechnologies.com ability to take away potential chemicals from rivers with farmlands and possibly factoires upstreams? I´ve looked at their webpage and the tests but it does not really tell me if it would be useful or not. Where I´m hiking the majority of my hikes I can choose between safe sources such as taps or well but that means carrying 3-5 liters or take water from rivers or creeks with chemicals from farmlands. That is why I am so keen on understanding the potential of the www.bwtechnologies.com

Thanks in advance.

No, their media will not remove chemicals or metals so would not be an appropriate match for municipal, industrial or agricultural waste removal.

The only portable technology that would is reverse osmosis. Katadyn makes portable R/O filters aimed at boaters. They're heavy and expensive but in certain cases could be preferable to lugging large quantities of water. (Note: Carbon can remove certain chemical and metal contaminants via adsorbtion but is not effective for all and the required carbon quantity and contact time differs for every contaminant. It's not an answer for unknowable contaminant mixes and concentrations.)

Cheers,

Rick