The cold and filter question...

[Chubbs4U]

I recently placed my Katadyn water filter and my Sawyer inline filter in my attic which gets particularly cold. Didnt think about it til recently. Couple questions, I know you arent supposed to let them freeze. How do you know if they are working properly? If they did freeze, what exactly do I have to replace? I thank you for the help.

[STICK]

As far as I understand, there is no way to test a filter. If you suspect that it may be damaged, the best thing would be to replace it. Depending on the model, the Katadyn may be able to be opened up and just swap the filter out. The Sawyer will have to be replaced all together.

[Hosaphone]

If you can blow through it, you know it's toast. However, just because you can't blow through it doesn't necessarily mean it's working as well as it should be.

[Chubbs4U]

I thank you both for a quick response. Its currently 28 degrees outside here and my attic is a little above 55 degrees so I think Im pretty safe considering it doenst get too much colder here.

[Ironbelly]

Unless the filter is wet you don't have to worry about it freezing. If it is wet you better watch yourself.

If your really concerned then don't store it wet or in your attic.

[G-FOURce]

Does everyone else set their filter out for several days when they return home from a hiking trip and let it dry?

[kidchill]

I can only comment on the sawyer squeeze...but from recent personal experience, I can tell you that it has to get pretty damn cold for the filter to freeze, as well as there has to be some water in it. You'll know it's frozen 'cause when you go to filter water at first light, nothing will come out! My sawyer froze when it hit 15deg one night. I hiked with it inside my shirt for about 7miles and it thawed out. I continued to use it for the rest of my thru hike. That may not be the best thing to do, but I wasn't sure if freezing meant it was permanently useless, or just unable to work while frozen. So, I took my chances since I only had a couple of hundred miles to go. I never got sick, so, there it is. I will say though, that filter worked great the entire hike, except for the mylar bag broke within the first 100miles...I had a platypus bag I wasn't using, so I just used that to complete my thru...

[Bucho]

I recently placed my Katadyn water filter and my Sawyer inline filter in my attic which gets particularly cold. Didnt think about it til recently. Couple questions, I know you arent supposed to let them freeze. How do you know if they are working properly? If they did freeze, what exactly do I have to replace? I thank you for the help.
You can test the integrity of your Sawyer filter, you've probably noticed that air doesn't pass through the hollow fiber filters. If you still can't push air through your Sawyer inline filter than it's fine.

[Bucho]

Here's the manual on how to check the Gravity Works filter for damage like I was talking about: http://media.cascadedesigns.com/pdf/cleanstream_filter_test.pdf

[Papa D]

Freezing is one of the main drawbacks of filters in general - - treating your water with drops is much more reliable and a lighter weight practice in my opinion (and I've toted a variety of filters)

[Odd Man Out]

You can test the integrity of your Sawyer filter, you've probably noticed that air doesn't pass through the hollow fiber filters. If you still can't push air through your Sawyer inline filter than it's fine.

I would trust this. I have used disposable ultra-filtration membranes in the lab for filter sterilizing cultures for growing bacteria. We would use a 50 mL syringe to push the liquid through the membrane housed in a cartridge that screws together to hold the membrane in place. When the liquid was through, you could push as hard as you could in the syringe plunger and no air would go through the filter. If that happened, you knew your filter was good and your culture was sterile. If air went through, you knew you had a cracked membrane and you would have to do it again. These were 0.1 micron filters, like the Sawyer.

[Slosteppin]

I store my backpacking gear in the garage. All except my waterfilters which are kept in a closet in the house.

If I left a filter in my cold garage in the winter that filter would be thrown away. It would be replaced in the spring.

[Sarcasm the elf]

Does everyone else set their filter out for several days when they return home from a hiking trip and let it dry?

I did that the first couple of times with my Hiker-Pro I also store it disassembled so that there's no chance of residiual moisture getting trapped inside.

Then I realized that it was a lot less work if I just didn't get it wet in the first place. ;)

[Bucho]

treating your water with drops is much more reliable and a lighter weight practice in my opinion (and I've toted a variety of filters)

During my thru hike three of my aquamira using friends got giardia so I can't say that I share your opinion.