When Ann and I started hiking we used a First Need water filter. Then we moved to the MSR Waterworks filter.
This pump was a very slow, it clogged easily, and it weighed more than a pound. In 1996, on the PCT, in the middle of the creek just north of Acton, I got so mad at the filter that we switched to the PUR Hiker at the next town. Note: Katadyn has since bought the company, but they have not changed the water filter. It is virtually identical to the Pur hiker.
We used this filter for many years. It was easy to use and maintain. Although, it did not filter very fast and it was heavy. As our family has grown, weight has became an issue and I started looking for a lighter filter system. In the end we started to use the Sawyer Squeeze and Sawyer Mini.
The Sawyer filters work great. They were light and they did not cost a lot, but they were not the easiest to use. We started with the squeeze bags. The bags took a lot of muscle and a good bit of time. I was filtering for four people and we did not look forward to pumping. Over time the bags would break down and start to leak at both the threads and in the neck of the bag. For one JMT hike we switched to a plastic bottle and it lasted longer than the bag, but was no easier to squeeze.
When we hiked the PCT in 2015 we tried a gravity feed system using a dirty water bag and a Sawyer Mini. This worked, but it needed improvements. On the CDT I put together a system that could be unhooked without water leaking out, it was easier to hang, and it easily connected to our hydration bags. It still took us 30-45 minutes to fully filter 8-10L of water. We did have some problems filtering in New Mexico because there were not many places to hang our bag. This system worked great until southern Colorado. I hung a full 12L dirty bag of water from a tree limb. Then, as I was getting ready to filter the water, the dirty bag fell to the ground and popped like a big water balloon. My gravity feed system was destroyed. Luckily Treeman, a thru-hiker we were with had a SteriPEN he was not using. We borrowed it until we got to Pagosa Springs.
Years ago I received a SteriPEN for Christmas and it did not work right out of the box. I returned it and got a second one. Within three months that one failed. I did not have much faith in SteriPENs. That was years ago. The SteriPEN Ultra is USB rechargeable, which is much better than the older battery version. I could charge it from my external battery. It would filter a liter of water in 1.5 minutes. That meant we could filter 8-10L of water in 12-15 minutes. The only drawback was floaters and we solved that by running dirty water through a bandanna first. When I replaced my gravity feed system in Durango I got a SteriPEN. We used that for the rest of the CDT and never had a problem. A word of caution, the SteriPEN can be fragile. Treeman dropped his from 3′ and it broke the UV light. We were very careful with ours.
All of used a hydration system. Ann, Will, and Joon have 2L Hosers.
I experimented with a hybrid system. I used the Hoser’s hose and bite valve, but the bag was a Sawyer 2L. The basic problem I have with the Hoser is the cost. It is about $26 for a bag, hose, and bite valve. But you cannot buy just the bag. If I get a big hole in one I have to dish out another $26, but I do not need the hose and bite valve. I need just the bag. This is the way Platypus gets you to spend more money. On the other hand the Sawyer 2L bags cost $9 for two and they have the same thread pattern.
The only problem I had was a weak spot would form if I carried the bag around the mouth. There is a hard plastic piece inside and it would wear a hole in the bag. When I started carrying the bag by a corner, I stopped getting leaks. This is a much more economical solution to replacing bags.
This is one of the best things we discovered when we hiked the PCT in 2015. Any pool supply store will carry vinyl pool repair kits. These patches are great at plugging holes in Platypus bags. Just cut a circle patch about 1/2″ larger than the hole, peel off the back, and place it over the hole. It will stick to wet surfaces.