Take a Hike: MSR Trail Base Gravity Filter System

Safe drinking water is a must in the backcountry. We all know that. Whether you’re running, camping, backpacking, or just out for a day hike, staying hydrated is a top priority and there are plenty of options of how to clean and sterilize your water. There are many factors to consider when shopping for your best fit, so consider the use-case, the number of people in your group, how much water you drink, how much water you’ll have access to, how much you want to physically carry during your activity, and what sort of technology you prefer. There is no “one-size fits all” but I tend to favor the gravity filter. I was lucky to get my hands on an MSR Trail Base Gravity Filter System – here’s what you should know about it.

From the website:

The Trail Base microfilter kit features modular components that allow it to be used as a gravity system at camp, a pocket-sized filter on the trail, or a fast-and-light reservoir when you need to carry clean water with you. Whether you’re hiking, biking or basecamping, the Trail Base water filter kit offers incredible flexibility and options, making it the one filter that truly adapts to your adventure and the filtration task at hand.

Right now, the MSR Trail Base Gravity Filter is available as a 2L system but they are rolling out a 4L in the spring, which I have to say was a great size for our backpacking party of 5 (plus baby). It has 3 different configurations, making this multi-use filter a great addition to the gear lineup.

The system comes with a 2L (or 4L) clean-water reservoir, a second for dirty water, a TrailShot water filter, a hose, and a carrying case to keep it all together. As it should, the reservoirs include straps for hanging / carrying and securing / etc. during filtration, quick connect hoses, and hose clamp to easily stop the flow and secure your water supply. The filter gives you a flow rate of 1L per minute with a cartridge life of 1,500 liters effective against bacteria (99.9999%), protozoa (99.9%), and particulate.

The TrailShot water filter can be purchased separately (for $49.95) if you’re interested in only that part, and while its inclusion to this system makes this a really versatile setup. To use the TrailShot on it’s own, simply drop the end of the hose into your water source and squeeze the filter / clean water into your vessel (or straight into your mouth!). To use the gravity filter, fill up the “dirty” reservoir, connect the hoses and TrailShot filter between the two bags (dirty reservoir higher because #gravity), and in a few minutes your clean water reservoir is filled for use. The clean water bladder can be easily inserted into your pack to carry as well or leave the bags at camp for your day outing and take just the Trail Shot and hose for a lightweight option.


Per the website, the entire 2L system weighs 1 lb 6oz, so it is still outside the “ultralight” range.  MSR has taken this into account and clearly made some adjustments for the 4L. Coming in at about 1 lb 4 oz for the 4L, the slight additional weight may be a trade-off worth making given the multifaceted use-case of this system.

MSR is a great company supporting athletes and adventurers with thoughtfully-made products. Semi-local, hailing from Seattle, I’m always a fan of their gear and this filter system is no exception. If you’re looking for a new one for yourself or someone else in 2019, check it out and consider it. It really is the “jack of all trades” of filters on the market right now.

CompanyMountain Safety Research (MSR)

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Product: Trail Base Water Filter Kit (2L) ($139.95) (watch for the 4L option this Spring!) | Amazon

Details (from website):

  • Effective Against: Bacteria (99.9999%), protozoa (99.9%) and particulate. Hollow fiber filter meets U.S. EPA drinking water standards* and NSF protocol P231 testing standard.
  • Versatile: Modular components allow system to quickly and easily transform from a 2 L gravity system into a small trail filter and back.
  • Simple Transitions: Trail filter simply quick-connects into gravity system to create the complete gravity-fed filter system.
  • Complete Kit: Includes ultralight, durable clean water reservoir, which features our 3-in-1 cap for easy filling, drinking and pouring.
  • *U.S. EPA Guide Standard and Protocol for Testing Microbiological Purifiers

More about MSR:

In 1969, Seattle engineer and lifelong mountaineer Larry Penberthy formed Mountain Safety Research as a one-man crusade dedicated to improving the safety of climbing equipment. The fuel behind Larry’s passionate fire was a simple belief that still drives our team today:


From that notion evolved a pioneering outdoor company whose innovations have revolutionized the way people experience the outdoors worldwide. Today, we’re a close-knit team still obsessed with designing the most reliable, high-performance gear possible, using our knowledge of engineering and science to find better solutions to the challenges of the mountains.

Thank you to MSR for providing us with a sample filter. Please read our transparency page for info on how we do our reviews.


About Author

Bobi Jo has lived all over the midwest but moved to Portland in 2007 and now calls it home. She started casually running in 2012 and trained up for the "Run Like A Mother" 5k as her first proper event. She got a taste of the runner's high and is now a veteran ultrarunner. While running is her favorite sport, she is a "Jill of all trades, master of none" - her other hobbies include rock climbing, hiking, skiing, mountain biking, snowshoeing, and traveling the world. On her elusive rest days, she is an avid bookworm and a Green Bay Packers fan.

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