MSR Autoflow XL gravity filter system

Posted by: Rick_D

MSR Autoflow XL gravity filter system - 10/05/19 03:38 PM

Rolled out this water bag-and-filter kit this summer and am really pleased so far. Probably overkill for soloing, at 12oz, but for two or perhaps more it's the fastest, most convenient filter kit I've used.

1. The 10L raw water bag holds enough for a full day in camp. It's tough, the roll-top is simple to close, the hanging system is effective and flexible.
2. The flow rate is faster than any gravity filter I've used. Compared to the Sawyer system I've used for many years, it's notably higher and the 1.75L/min spec may be correct. I've not stopwatched the thing. (They use the same filter media.)

MSR doesn't match Sawyer's lifetime cartridge guarantee and no backflush device comes with the kit. But, the Sawyer backflush hose can be adapted so it can be routinely flushed at home. Field-flush is possible using a clean water bag attached with a hose, similar to the Sawyer system. As always, you need clean water to backflush so don't wait until the flow is zero!

How well does it work with sketchy source water? I don't know.

Worth a look for anybody in the market for a new filter.

Posted by: Glenn Roberts

Re: MSR Autoflow XL gravity filter system - 10/07/19 12:11 PM

I used both the MSR Autoflow and the Platypus GravityWorks within the last few years, and found them both easy to use and to backflush. The filters are identical; the only difference is the reservoir materials and the "clean" bottle fittings. (The fittings had nice covers for limiting cross-contamination.) I liked the wide opening for scooping water; being able to re-seal it securely allowed me to use it to carry water to a dry camp. I was using a 2-liter "dirty" bag with each; I'm wondering if 10 liters might be a little awkward to lift and carry when you're perched with one foot on the muddy bank and the other on a moss-covered wet rock while you fill the bag.

Backflush is easy: just lift the clean bag higher than the outlet on the dirty bag, and let clean water flow backward through the system. I never had any problems with this working. The dirty reservoir in both systems is nicely designed with an inch or so of space below the outlet where sediment and other crap can settle out, and not get sucked into the outlet. Very thoughtful, and something you can't do easily with the Sawyer.

In the end, I went to the Sawyer Squeeze for the simple reason that I got tired of fooling around with the hoses on the MSR/Platy setups (I use the "cleaning coupler" to attach the clean bag.) I also replaced the Sawyer bags with Evernew collapsible bottles - including one that has a wide opening on the end for scooping up dirty water.

However, I don't believe you can go wrong with the MSR Autoflow or Platypus GravityWorks system.
Posted by: Rick_D

Re: MSR Autoflow XL gravity filter system - 10/07/19 05:40 PM

Thanks for the backflush tip, seems simpler than Sawyer's "Fill and close supply bag, connect filter and press bag" routine. Have only needed to do that a few times, but learned to get on it before flow completely stops. And backflush before storing your filter until next season (ask me how I know).

Filling the 10L bag can be more challenging than the Sawyer supply bag with the handle you can dip into the water, but a cookpot scoop has been good enough so far. A dinky stream or weed-choked shoreline is always a test, no matter what I'm toting. An added design feature I assume is intentional--the bag outlet is a couple inches from the bottom. Fine particles can settle out below the outlet so as to not get into the filter.

Now that companies seem to be using standard hoses and connectors, mix-and-match possibilities are limitless. That only took a couple decades. smile
Posted by: Rick_D

Re: MSR Autoflow XL gravity filter system - 10/14/19 11:41 PM

Some follow-on comments after a mid-fall 5-day trip.
  • Camped at a ginger ale-colored meadow lake that noticeably slowed flow, and a clear-water backflush sped it up nicely. The best indication it's slowing is difficulty clearing air from the lines and filter.
  • Good for MSR using clear silicone tubing. It doesn't kink, doesn't flavor the water, doesn't stiffen when cold, and doesn't hide air bubbles.
  • The 10-liter bag opens up dry camp options. Lug 20+ pounds of water in from the nearest source and you'll be good until the next day.
  • Don't forget to bring the filter cartridge into the tent on sub-freezing nights. Pop it into a ziplock bag to keep things dry.