Forum Index » Editor's Roundtable » A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods


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Stephen Gerrard
(StephenG) - MLife

Locale: Australia
How do you know your hollow fibre filter is not damaged? on 08/24/2012 19:34:09 MDT Print View

Is there a way of testing a Sawyer filter's integrity?
How can one be sure the filter did not accidentally freeze or sustain damage from a fall / impact?
Wouldn't it be nice if there was a way of proving it works, even just for peace of mind - like can be done with the MSR product?

This is the one thing that has kept me from buying one.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Freezing or Dropping on 08/25/2012 08:04:29 MDT Print View

From sawyer.com:

"Q. Can the filter be frozen?
A. While we have no proof that freezing damages the filters we have no proof that it does not. Therefore we must recommend replacing the filter if you suspect it has been frozen."

From article, Roger says when you backflush, the tubes expand a little which helps dislodge any blocked pores.

If the tubes were full of water, froze, and expanded a little it doesn't seem like it would burst the tubes.

Putting filter in your sleeping bag doesn't seem like a very good solution. Hard to reliably keep your filter from every freezing over many trips. Before and after sleeping you'de have to carry it in your pocket?

Too bad there isn't some way to test a filter after it's been frozen a bunch of times.

I am tempted to just shake the filter out really good if it might go below freezing.

Besides, you don't really need to filter the water anyway. This is just a made-up issue so filter manufacturers can sell filters : )

HK Newman
(hknewman) - MLife

Locale: Western US
Re: A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods on 08/25/2012 08:59:28 MDT Print View

I definitely needed this update in the latest in water treatment. I'd gotten away from filters after a popular but now defunct brand's best seller shattered. Pressed down on the plunger and the body cracked into many pieces.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods on 08/25/2012 10:59:44 MDT Print View

I had a PUR and it cracked when I pressed on plunger. It still worked good enough for that trip, then I put tape on it and used it for a few more trips.

Rick Dreher
(halfturbo) - MLife

Locale: Northernish California
Re: Freezing or Dropping on 08/25/2012 11:48:47 MDT Print View

"Putting filter in your sleeping bag doesn't seem like a very good solution."

Why?

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Freezing or Dropping on 08/25/2012 14:49:32 MDT Print View

Because it's freezing before and after when I'm sleeping so I'de have to carry it in my pocket.

Lyan Jordan
(redmonk)

Locale: Greater Yellowstone Ecosystem
Test the water filter on 08/25/2012 14:55:30 MDT Print View

Too bad there isn't some way to test a filter after it's been frozen a bunch of times.

How much would you pay to have your filter tested and certified ?

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Test the water filter on 08/25/2012 15:00:38 MDT Print View

"How much would you pay to have your filter tested and certified ?"

I would like Sawyer to test their filter (after freezing) and report the results : )

T N
(tordnado) - MLife

Locale: Europe
Re: Re: www.bwtechnologies.com on 08/26/2012 23:37:13 MDT Print View

Thanks for the comment. According to themselves they DO remove chemicals. I have been in contact with them and both their webpage and their E-mail answers claim that they do. I have requested a test report.

If bwtechnologies actually remove chemicals I will choose it before the Saywer filter however if they cant back up their claims the Saywer stays on top!

T N
(tordnado) - MLife

Locale: Europe
www.bwtechnologies.com on 09/06/2012 10:18:12 MDT Print View

I have benen trying to get an answer from www.bwtechnologies.com for quite some time now! The first replies where prompt and good but when I asked about a test report they have not gotten back to me at all! Suspious!

Hikin' Jim
(hikin_jim)

Locale: Los Angeles, CA, USA
Re: A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods on 09/11/2012 12:31:11 MDT Print View

It seems like the one really serious drawback to filtration is that there's no way to verify that it's working (short of having access to a very sophisticated laboratory).

With boiling, I can feel the heat and see the bubbles. With a Steripen, I can observe the light. With chemicals, I can taste and smell the chemicals. There's no way of knowing if a filter is working. What if I got the "lemon" out of that last production batch?

Is anyone aware of any studies that might give us an idea of how many failures per "X" number of filters manufactured there are?

Is there any way to garner an idea of how effective filters really are?

HJ
Adventures in Stoving

Jim Milstein
(JimSubzero) - M

Locale: New Uraniborg CO
Re: Re: A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods on 03/17/2013 13:21:14 MDT Print View

I made a female/female adapter by hot-gluing two bottle caps together then drilling a hole through the unit. I also made a narrow-mouth adapter for the Nalgene wide-mouth Cantene, which fills much easier than a narrow-mouth bottle or bladder.

So, if you squeeze dirty water from the Cantene through the filter into another bladder, connected with a F/F adapter, you are set up for a back-flush by simply inverting the arrangement and squeezing a bit of the clean water back through the filter then discarding the wash water from the dirty water bladder. Though it is unnecessary to do this often, it is trivially easy to do.Narrow mouth adapter for Nalgene wide mouth lidSawyer Squeeze Filter on Nalgene CanteneSawyer filter from bladder to bladder via F/F adapter.

Ken Thompson
(kthompson) - MLife
Re: A Survey of Water Hazards and Water Treatment Methods - Part 5: Filtration Methods on 03/17/2013 13:34:17 MDT Print View

If you don't want to make your own. Look at these.



http://jetflow.com/product-detail/?pid=247