MSR AutoFlow Gravity Filter

Love this filter. 4 liters of water with no pumping. It is quick and easy to manage. Worked great for a group of 4. Your old water jug now serves as the dirty water reservoir waiting to be poured into the bag. Easy to hang. Lid adapter fits nearly every water container we tried.


Minor flaw: Research the flaw & you will see that a tiny hole can be drilled to prevent vapor lock when backflushing (or you can just leave the lid loose). That didn't stop the 10 stars...


Biggest drawback (-1 star): replacement filters cost almost as much as the whole system.

This is a great filter for large groups or just for two. Puts out plenty of water in a short amount of time. One of the Pros of this gravity filter over others is the fact that the outlet on the bag is slightly above the very bottom of the bag, which is good as then all of the sediment goes to the bottom of the bag and not down the hose into the fitler element. On other gravity filters the hose to the filter comes off the very bottom of the bag so all of the sediment goes down the hose to the filter element, thus clogging it up quicker.

We switched over to this from a hand pump and it has worked great! We even bought an extra 4 liter red bladder so that we could paddle out and scoop a total of 8 liters to filter at once. We also augmented the filter system with a 10L MSR water bladder and 2L red MSR water bladder to catch and hold as much water as we could ( We are a family of 4!). The filter mechanism works great and is easy to maintain. Whenever it slows filtration, we can lift the bottom bladder up to relieve the potential air-locking inside the filter or backflush with a minimal amount (1/2 L?) of water from the bottom bladder --- all in a minute or less. The filter then works fantastic again. Love this set-up and won't ever go back to the hand pump!

This is a great set-up for filtering water in camp. We have 4- and 6-liter collection bags with the microfilter and two collection bags. We can get 10 liters quickly from the lake and fill everyone's water bottles repeatedly in a group of 4. It all packs up neatly in a small stuff sack for travel. The only downside is frequent backflushing of the filter but it is quick and reliable and produces a great quantity of clean water.