KC8QVO

'nuff said.

I use their 10L bag filter with a carbon filter in the hose. It might appear to be "overkill", but the size is absolutely wonderful. I've been on backpacking trips where, as a group, we had a water filter pump of some kind. We would take turns at a stream filling up a nalgene bottle or two. That was a real PITA. I forget when, but I came across the gravity filter systems. There are a lot of options and Sawyer (also mentioned earlier in the thread) is popular for using their filters in home-made gravity filter systems. The Katadyn set up seemed easier out of the box. I think back when I got mine it was noticeably more expensive, but given it was a system ready to go that's why I got it.

I can honestly say it is one of the best things I've bought for camping.

The only critique I have is that when you fill it up it is heavy. However, that weight is a good thing when you are in camp and not moving for a few days. If you don't need much water - just fill up a liter or two.

Personally, I like having a surplus of water. If I don't have a stream right in camp knowing I have the capacity in the bag is great. That means I can wash dishes, my hands, brush my teeth, etc and I don't have to "conserve". It just makes camp so much easier.

One item of consideration, and I don't really consider this a critique because it is how these function, is that the water out of the hose is a small trickle. It takes a few minutes to fill up a nalgene bottle. It sure beats the pants off of pumping though. Set it up and let it drip, then go do something else in camp for a few minutes. When you come back you have a fresh bottle of water. I like it!