Viability of filtering water in freezing (MSR Guardian)

Hummm . . .
It seems to me that you can NOT pump water through a frozen filter.
Me, I use a Steripen UV wand.

Cheers

If frozen, it wouldn’t be too hard to thaw by keeping it inside your jacket I think. But maybe it’s not worth the hassle.  I was thinking it would be nice to have clean/clear water without any dirt/debris floating in it.

That would certainly take away the fear of accidently freezing your filter. As noted it would need to be thawed in order to use, so you can use any filter (but other filters would need to be always kept thawed). HYOH, if that is an important feature for you and you don’t mind lugging around the 3 pounds go for it. If the water sources are relatively clear, I’d personally go with a steripen and bandana. This beast seems well set up for muddy dirty water as it keep flushing itself clean. I remember a rainy desert that would have been nice.

steripen has lithium battery which doesn’t work well or at all, below freezing.  But you can put it in your jacket to warm up.

They say not to let a Sawyer Squeeze freeze.  But I always shake all the water out after use so there’s only water in the tubes.  And I’m sure it’s frozen.  Still seems to work the same.  It’s too bad they don’t test this.  Hmmm… I have some cerium oxide powder that I used to remove a scratch in glass, that has a particle size somewhat greater than the pore size of the Squeeze, I could test that…

HYOH, if that is an important feature for you and you don’t mind lugging around the 3 pounds go for it.

I think the Guardian purifier is more like 1 pound. But yeah, it’s extra weight for sure. In the winter though could be convenient I was thinking. It seems Steripen is the more popular choice however.

@ Jerry I had thought that if water is inside the hollow fiber filters like Sawyer and Platypus, in cold weather, the water can freeze and break the hollow fibers.  Water can still pass through the filter afterward but there is no purification/filtration occuring.

@ Giles. It is just you or are you in a group?  Are you base camping or changing campsites day to day.  I have been out with groups snow camping in the Sierra Nevada and when a lake is accessible, filtering water is much easier than melting snow. Our weather is a bit warmer that the temperatures you indicate.  I would just take the method you are most familiar with.

BTW Ryan Jordan wrote an article last winter or the winter before here at BPL and described how he used his MSR filter in winter in temperatures much like you describe.  I recall he was using ice screws to get access to the flowing water in streams.

I think the problem with the Squeeze freezing is when there’s water inside the case, outside the tubes.  (and water inside the tubes).  Then the case cracks.

The tubes are designed to expand.  When you backflush they expand a little which helps dislodge particles from the pores.  It seems like if they froze it shouldn’t be a problem.

But Sawyer is not interested in this.  It’s easier to just tell people to not let it freeze.

I don’t have really have a problem with this.  It’s more reliable to just not let it freeze.  Don’t rely on people to shake the water out of the filter.  Most people don’t backpack in freezing conditions.

And I’m not recommending that anyone do this.

I tried to keep it from freezing, but a couple times it got quite cold that I didn’t anticipate.  Now, I’m just too lazy to replace it.  It requires about the same pressure to squeeze.  It filters out tannins about the same as always – the output water is somewhat less brown than the input.  And when I backflush, there’s a lot of brown that comes out.

I was under the impression that the problem with freezing was a problem with hollow fibre filters such  as the Sawer Etc.  The fibers of the hollow filter become damaged if the water they are in expands/freezes.

I has a MSR many years ago that looks very similar to the guardian.  Im don’t recall the model.  It might have been a guardian. or its predecessor.

IIR, the filer is a solid ceramic element, way tougher than hollow fibers.

my .02

My old PUR filter has a membrane.  It withstands freezing just fine.  I think they still sell them.

1 pound

I just looked at REI.  It’s called Katadyn now.  They say it’s 11 ounces.

Steripen. I use mine all winter with no issues below freezing temperatures.  If its -10°F you may have a hard time finding water.. So realistically in those conditions I/You would be melting snow or ice for water.. Then no need for heavy filter anyway.

I use Katadyn chlorine dioxide tablets and/or a Steripen for all seasons. No more heavy water filters for me. If the water source has floating or suspended stuff in it I use a #2 coffee filter for my bike bottle.

I use that bottle to fill my Camelbak hydration bladder and to carry electrolyte drink.

Steripen has nothing to freeze. I use an Adventuror. Even the batteries can be replaced. IFF the tubules in a filter freeze, the ice can expand and split them,..like a frozen pipe in your house. IFF they are plastic and withstand the internal movement from the expansion, they will still work.