When I first started backpacking, we got the MSR Mini Works Pump Filter. It was the best thing on the market at the time. It was1.03 pounds and about $80 and was time consuming. While one of us would start camp set up, the other would sit by the stream or puddle and pump water for what seemed like hours. It would take at least a half hour to pump enough water for dinner and to fill our water bottles for drinking water. Then we'd have to do it all over again before we left camp to have drinking water for the hike the next day. Sitting by the stream and having some quiet time was nice, but honestly, your arm would get tired and the motion of pumping would get old after days on the trail.
The next system we grabbed was the Sawyer 2 liter – 2 bag gravity fed system. We didn't shave much pack weight off at about 12 oz, compared to the MSR, but we were excited about the idea of being able to hang it from a tree and go about our business while it filtered. It was expensive with an MSRP of $119 for the dual bag system. But from the first moment we tried it, we were in love. When we got to camp, we filled the dirty bag and hung it from a tree, hooked up the clean bag on the ground and walked away.
The filter was done before we unpacked our packs. It can filter 2 liters of water in as little as 1.5 minutes! Amazing! Now we had a way to do other things while filtering water! The whole system comes with a faucet adapter to do a really good backwash treatment when you get home. You can also backwash on the trail pretty easily. To this day, I still have that same gravity system. It has lasted about 8 years and is still going strong, so the money was well spent in my eyes. The only reason I will need to replace it would be simply to have a new one at this point. I have ordered a replacement filter just to have a back up.
It has garnished the coveted Backpacker Magazine Editor's Choice award, is super light (only about 3 oz.), relativity inexpensive (about $20-$30 for the system) and is touted to be the best and quickest way to filter water in the backcountry. Moreover, the filter itself can be used in many combinations of water vessels, so the versatility is above and beyond other systems. I was so excited to try it because I had read countless reviews from many sources and all of them were great news!
The first time I used it, was the first night of my 5 day solo backpacking trip to the Weminuche Wilderness in Southern Colorado. I had just gotten to camp. It had been a pretty warm day and I was pretty tired. Filling up the bag that came with the filter wasn't as easy as the wide mouth opening on the gravity filter I was used to. Also, the mini system only comes with a 16 oz. bag. Not the best for filling a 2.5 liter hydration pack. It would take 4 times of squeezing this thing into my hydration pack to fill it. Now, you can hook this filter up to your hydration pack to make it an inline filter system. This would definitely make it easier. However, when you install it this way, it is a pretty permanent retrofit. I wasn't ready for that level of commitment. If 16oz bag isn't large enough for you, you can try the Sawyer Products PointOne Squeeze Water Filter System. It comes with 3 BPA free pouches, 16,32 and 64 ounces.
All in all, I think that this system is great for day hikes and as a back up system on the trail. But I found myself on the third night of my trip being very envious of the other tippers in camp that were using their gravity filter. I missed mine terribly. It was like I was back in the pump days, where I had to be so active in my filtering process. My gravity system spoiled me into being able to get everything done to set camp and then just enjoy the view. Some may call that lazy, I like to think it's just plain efficiency in enjoying nature.
On my latest trip to The Wind River Range in Wyoming, I carried my 2-liter, 2-bag Sawyer Gravity System as my primary. My secondary was the Sawyer Mini Squeeze filter with one 16oz bag. I used the gravity system in camp to fill my hydration pack and for cooking. On my day hike to the Titcomb Basin, I carried one nalgene full of water but refilled my nalgene and drank straight from the squeeze filter, like a water bottle while I was hiking. This seemed like an ideal set up for me. All of it made getting water almost an after thought because it was so easy to keep up with. What was also nice was the feeling of being able to drink as much as you want, pretty much whenever you wanted. It almost felt like it was a water on demand system. TOTAL WEIGHT: 1lb, 4oz