I have an MSR gravity filter system that I bought in 2009... which was the last time I've been to the BWCA. Do those filters expire with age? It only has one trip on it so I'm sure it didn't meet the volume requirement for replacement.

We no longer have any kids in diapers so we're planning to return this year, and hopefully for many years to come. Thanks.

Our First Need filter says to test it with dye. If you can filter dye, it's still good.

Is there a chance it froze at any point with moisture inside of it? If so you probably need a new one. Otherwise I would imagine it's just fine. Might be mold/mildew growth if you put it away without a good flush/sanitization.

I'm sure it's fine but yes you should run a light bleach solution through the filter before storage. However being that it is well over a decade old and drinking water is something I never take lightly I would just get a new one. I'm sure the gravity filter technology has increased immensely in that time as well.

Run some diluted bleach solution through it, then flush with clean water with a few gallons. This will kill any nasties in the bag, filter and hose. A 1/2 cap of bleach per bag full of water will do the trick. Then flush with a couple of bags of fresh water.

Savage Voyageur: "A 1/2 cup of bleach per gallon of water will do the trick. "

A 1/2 cup? I don't know how well that would rinse out of a filter but that seems to me like a lot. Now all I can smell is bleach.

My Sawyer filter recommend a capful of bleach for 4 liters. IMHO, 1/2 cup is overkill.

After reading my first post I misspoke. That’s too much. I meant to say a half cap, no idea why I said cup. Just flush a few times and it will go away. I will change my post.