A lot of first-time backpackers use the Katadyn Hiker Microfilter. It’s easily found in most sporting goods stores and only costs $70. It is a great filter that is light, small, and rarely fails out in the field.
Since we were due for a new replacement cartridge ($50) I decided instead to try the Sawyer Squeeze system. For about $40, I got entire new system that includes the filter, squeeze bag, and flushing syringe. The Sawyer Squeeze is 1/2 the size of the Katadyn and weighs 1/2 as much.
While the Katahyn uses a pump and hose system to deliver clean water to any water bottle or pan, the Sawyer relies on muscle to force water from a 32 oz. Mylar bag through the filter.
In our real-life test in Glacier National Park, we were very happy with the way the Sawyer worked. I had learned in advance that it is difficult to fill the Mylar bag from a standing water source like a lake, so I brought a large zip-lock bag along which I used to fill the Sawyer bag. Filling the bag is much easier from a stream. Once the bag was filled, I simply screwed it onto the filter and began to squeeze out pure, clean drinking water. It took about 2 minutes to fill one Camel-Bak reservoir.
The Sawyer Squeeze filter is guaranteed to purify 1 million gallons of water. There are no moving parts, so the system should be very reliable. It is possible to split the Mylar bag, so it would be wise to be cautious using this in very cold conditions. The system comes with syringe that is used to back-flush the filter. We carried this with us on our trip, as it only ways an ounce or two.
PERFECT FOR: All backpacking trips that require filtered water
PROS: Very light. Simple operation.
CONS: Requires effort to squeeze the Mylar bag. Bag may fail under extremely cold conditions.