MSR Guardian Water Purifier ...and Why It’s Worth It!

By Dave F.

Why I chose the MSR Guardian.

We’ve all gotten sick from something that we’ve ate or drank. It could have been something we’ve consumed a number of times before without any previous issues, like water for example. After contracting Norovirus a few years ago, I said to myself, “I never want to go through that again”. I couldn’t eat, I couldn’t drink and I couldn’t sleep without getting sick.

When I first saw the MSR Guardian I thought, WOW that’s a beefy water filter! Then I saw the $350 price tag and thought, “man, for that much I could upgrade my pack, get a really nice pair of backpacking boots, upgrade my backpacking stove”, the list went on and on. I set it back down on the shelf and forgot about it. Later that day the Guardian popped into my head again and I needed to investigate the justification of the hefty price tag. I’ll tell you what, I was blown away by what I learned leading up to my purchase of “the world’s most advanced portable purifier”.

Evolution of the MSR Guardian?

MSR was tasked by the US military to create a water purifier that our troops could use anywhere in the world and not have to worry about waterborne illness. It needed to be fast, compact, simple to use and most of all, it needed to PROTECT. After six years of design, development, testing and field use, MSR introduced the Guardian Purifier to the outdoor gear industry. Fast forward a few more years and the MSR Guardian has rightfully won numerous awards from companies like Backpacker Magazine, Gear Junkie and Outdoor Gear Lab.

Design and Technology

Let’s dive into the inner workings of the MSR Guardian and find out what makes it FAST, SIMPLE and SAFE. The Guardian treats up to 2.5L of water in 60 seconds. That’s enough water to make 5 Mountain House, Chili Mac with Beef entrees!
To use the Guardian, remove it from the included pouch, un-coil the hose, toss it in your water source and pump, that’s it! The large pre-filter on the end prevents larger debris such as leaves and algae from entering the purifier.
As the water makes its way into the body of the purifier, it enters MSR’s game changing hollow fiber filter where all the magic happens. To make this easier to visualize, take a plastic straw and poke as many tiny holes in it as you can with a sewing needle. Now do that to a couple hundred straws and bundle them all together. The result is a simple version of a hollow fiber filter. MSR skipped the plastic bendy straws and went straight to medical-grade hollow fibers with thousands of microscopic “pin holes” running the length of each fiber. These pin holes are so small, viruses that would pass straight through a common ceramic filter like Norovirus, Rotavirus and Hepatitis-A can’t fit through these pin holes. This allows the treated, clean water to continue its journey to your drinking vessel. Not only has MSR created a way to filter out viruses, the medical grade hollow fiber filter can withstand freezing temperatures. Gone are the days of having to carry your filter on your person or throwing it in the bottom of your sleeping bag at night to prevent the filter from freezing and cracking rendering it useless. It has also been drop tested to ensure it can withstand drops up to 6 ft!

What do you mean it won’t clog?

What makes the guardian even more impressive, is its “self-cleaning” functionality. With every pump stroke, the Guardian is taking 10% of that clean water and flushing it back through the pump to rid the filter of all that nasty stuff it just collected. This means no more taking your filter apart and scrubbing and more importantly, a longer filter life! The hollow fiber filter in the Guardian is rated to treat up to 10,000 liters of water! That's enough to fill your 1L Nalgene bottle up twice a day, everyday, for 13 years straight! Did I mention the protective cover on the bottom of the filter housing has the same thread pitch as a standard wide-mouth Nalgene bottle? Hey, That’s pretty neat! No more awkward aiming techniques needed to get my filtered water safely and efficiently into my water bottle.

Who Needs the MSR Guardian?

I know, I hear what you’re asking, “Can’t I just boil my water?”, “Iodine drops are really cheap.”, “Can’t I just use my UV light pen?” While these methods are certainly effective at treating water for viruses, they aren't always practical or easy to do. Let me give you some examples.

Scoutmaster Chris is on a backpacking trip with his group of 15 scouts and 3 additional adult leaders. It’s dinner time and they’re ready to start making their freeze dried meals.

While boiling their water could be a safe way of making sure the water they just scooped out of the nearby creek is free of viruses and bacteria, they’re going to be there all night boiling a liter of water at a time on a few small pocket rockets, or trying to bring that giant pot of water that took up 1/3rd of someones pack to a boil. At 2.5L per minute, the MSR Guardian will have everyone eating in no time giving them plenty of time for a campfire before lights out. The Guardian is a great addition to the troop box for purifying large quantities of water in a fast amount of time while ensuring all the scouts are consuming clean water without the risk of getting sick.

Mary is heading to Peru for a month long trip and is nervous about the water she might be drinking while out on her hikes or while jumping hostel to hostel. She thought about buying bottled water when she gets there but doesn't want to carry all that weight and doesn't want them to end up in a landfill.

No worries, Mary, the MSR Guardian is an excellent choice for your hydration situation. Just pack a few wide-mouth Nalgene bottles and you’ll be good to go! Close the drain on the sinks in those hostels, fill them up with water and pump away! Now Mary has clean water for drinking, washing her face and brushing her teeth. Guess what Mary doesn't have? A waterborne illness causing her to cut her trip short before she gets to see Machu Picchu!

Matt likes the idea of a UV lighted pen to treat his water while backpacking, it seems simple enough to use. Swirl it around and done, right?

While Matt’s UV pen is a good back up option to eliminate viruses and bacteria, he’s still going to need to pre-filter the water if it’s pretty funky. The UV light in Matt’s lighted pen needs to be able to reach all of the water in his vessel to work effectively. Water that is murky or full of sediment or debris is going to prevent the UV light from killing all of the viruses and bacteria that might be hiding in there. Matt can invest in a good quality water purifier like the MSR Guardian and he won't have to question if that water is clear enough to treat before he drinks it.

My Final Thoughts

While the MSR Guardian isn't the cheapest or the lightest weight option out there, the features, benefits and peace of mind that the Guardian has to offer outweighed that expense and I’m glad I spent the extra money knowing I was protected from whatever waterborne microbiological threats that may be lurking in my water while backpacking and travelling.

Stop by Appalachian Outfitters to see the MSR Guardian and learn about safe and effective water purifying methods!