Having problems with my gravity bag filter. Got the big filter working, but the outlet valve (where the hose attaches) doesn't let water through. I'm thinking of just drilling through the valve (there is a small white piece of something in there) to open it up. I don't believe this is a filter, so would this work ? I've done all the correct cleaning and storage, but this thing has been slowly going downhill. If I buy a replacement filter, does it also come with the outlet valve ? I looked at the REI website, all that is pictured is the big filter.

I took an old filter from our Katadyn and drilled it out so there is no filtration in it. I use it with a sawyer inline filter with it when my bag filter slows down or quits flowing

I thought I was having trouble with my Katadyn Base Camp 3L filer last fall but it turned out I was connecting the wrong end of the hose to the filter. Both ends will fit but only one will allow water to pass through. Not saying this is the issue, just putting it out there as something to take note of.

bombinbrian: "I took an old filter from our Katadyn and drilled it out so there is no filtration in it. I use it with a sawyer inline filter with it when my bag filter slows down or quits flowing "

Did the same to my Katadyn and put a Sawyer mini attached to the hose outside the bag. Worked great on our trip last week and we were dealing with cotton and pollen throughout the water. For pics on how to convert your Katadyn to use the Sawyer mini check out the search mode. We were going through Katadyn filters like crazy before the conversion.

Now this is going to sound dumb, and that's because it is. Shrewdloon, you put me onto the problem-the hose. Don't ever leave the clamp at the outlet end clamped. I did, evidently too long, and the hose stuck together and prevented the valve from working, which prevented water from flowing. I was at the point of doing some other options with my sawyer stuff. Thanks for the tips everyone. Who knows, I may need them later.