Not in the field; I tried. Used the tube connected to water bladder, using boiled water. I will work on it at home now that I'm actually at home for the week. Considering that it was tested with tap water and worked just fine shortly before the trip, why was it blocked the first time I tried to use it in the field?

Good question. I'd try contacting Sawyer support and ask.

I have the older version. Plus, all my bladders are dirty. My syringe is pretty light, Plus I can use it to irrigate wounds.

Oregon Mouse,

I've had this occur several times within the last year and have talked with Sawyer about it. They recommended backflushing it under a hot water faucet and/or soaking it in vinegar then backflushing it. This has worked for me. Takes about a half hour of fiddling to restore full flow.

More recently I've been using the technique shown in the link below:

http://www.backpackinglight.com/cgi-bin/...t=683345#683345

For me the problem might have been associated with using bleach (per instructions on water bags) to disinfect the filter. Have you used bleach at all?

Sounds like they are worried about calcium or hard mineral build-up.

By the way DJ, love the high pressure hose technique.

I think that probably floaties sinkies and swimmies in the water clogged up the filter system so that may be the reason.
-Nate-

Nate,

I didn't mention this in my post but the problem occurs between trips not after trips. The filter would flow well after backflushing it when I store it. When I took it out of storage after a few months, however, the flow was greatly reduced. So I think the problem has more to do with some aspect of the drying process (in my case) than floaties etc in the filter.

Am convinced after three seasons of use that the Sawyer cartridges cannot be completely dried. Even after weeks sitting in a sunny window I can still get water drops out of them.

My takeaway is it's very important to do the chlorine solution backwash before storing for the winter, then at the season's start, backflush before the first trip.

Some combination of bacteria and/or mildew is at work during that off period, clogging the works.

As to how visibly clear water clogging the filter in the field, it's likely to be bacterial biofilm. Have found field-backwashing can restore flow, even though it's a pita to do.

Cheers,

Rick,

"Am convinced after three seasons of use that the Sawyer cartridges cannot be completely dried. Even after weeks sitting in a sunny window I can still get water drops out of them."
I agree and someone awhile back actually cut one open and confirmed same. Was that you?

"My takeaway is it's very important to do the chlorine solution backwash before storing for the winter, then at the season's start, backflush before the first trip."
I also agree with this and it is what I've done in the past. The reduced (almost no) flow problem occurs when I remove it from storage and am preparing it for that first trip. That's when I have to backflush, forward flush, soak in vinegar, etc. Takes about a half hour of fiddling to get it flowing correctly again.

"Some combination of bacteria and/or mildew is at work during that off period, clogging the works."
Maybe so. I don't really know the cause. Others have guessed it is the bleach or Seattle water.

"As to how visibly clear water clogging the filter in the field, it's likely to be bacterial biofilm. Have found field-backwashing can restore flow, even though it's a pita to do."
Haven't had a flow problem in the field yet and I've used it for up to a week at a time.

So far this year my pressure nozzle backflush (see link in post above) before and after each trip has kept things flowing nicely. Won't be putting it into storage again until Oct so we'll see what happens next spring.

In one of the links above, a poster made this comment,"Most of the reports of the Sawyer filters slowing to a crawl (my inline did this) are when the filter dries out in storage, not usually on a hike."