MSR MiniWorks EX Microfilter Review

MSR MiniWorks EX Microfilter
MSR MiniWorks EX Microfilter

I had to think for about three seconds about what item in my Bug-Out Bag I wanted to review (Coincidentally, if I have to think seriously for more than ten seconds, I can smell burning – maybe taking care of fire-starting needs? More to follow. – Mike). Clean water is essential to our survival, and needs to always be at or near the top of a priority list. With that mind-set I wanted to do an MSR MiniWorks EX Microfilter review. There’s a reason why you’ll find this product ranked high in any list of water purification products, but being the Doubting Thomas that I can be, I had to see for myself.

Last year I had the pleasure of getting on a 10-day canoe trip to Turtle River – White Otter Lake Provincial Park with some co-workers. I was quickly convinced of the value of the MSR Microfilter when I was told I wouldn’t need to worry about fresh water when we were up there. I wouldn’t dare say the park was untouched by man (after all it is a park), but in open lakes I felt comfortable dunking my water bottle an arm’s length for my drinking water. As a rule of thumb, in a remote freshwater lake, if you are to look for drinking water and have no purification, remember to draw your water away from shoreline and from at least a 1 1/2 to 2 feet under the surface of the water, to avoid surface contamination. This is your best bet to avoid contamination, but by no means is a sure-fire replacement for water purification. And please, PLEASE don’t think that rivers fit this rule. Three words – beavers love rivers. Contrary to popular belief, going through a bout of the pain and dehydration of beaver fever is far worse than Bieber fever, even though we would never admit it. If beavers aren’t local to your area, there are certainly other critters that keep the rule relevant.

Anyways, the MSR Microfilter – awesome. As with anything, there are several pros and cons to ownership:

PRO – Keeps going, and going, and going

MSR MiniWorks WaterWorks EX Ceramic Element
MSR MiniWorks WaterWorks EX Ceramic Element

The MSR MiniWorks EX Microfilter comes equipped with a replaceable Ceramic Element. The cartridge is good for 2000L of clean drinking water before replacement is necessary. The cartridge itself weighs 3.8 ounces, so the presence of one complete Microfilter and a spare cartridge represents roughly 4000L of clean drinking water – much more than an individual or family would need over a 72 hour emergency period. Concerning sheer volume of clean water produced, the Microfilter fares well.

PRO – Nalgene Friendly

The 32 oz. Nalgene Bottle (available in so many colours!) is the ideal companion for the Microfilter, for two reasons. First, the Microfilter is made to fit the lid (it will screw right on top) and second, it doesn’t take too long to fill up, relatively speaking. Depending on expectations,  how water is collected could be seen as a limitation, which leads me to my next point.

Nalgene Tritan Wide Mouth BPA-Free Water Bottle
Nalgene Tritan Wide Mouth BPA-Free Water Bottle

CON – Pumping is a pain in the…

…neck. Admittedly, I’m still using my first ceramic filter (haven’t needed to drink that much water). From my experiences with a well-used Microfilter however, I know that over time pumping becomes more strenuous with time. The advertised 1L a minute is probably an ideal, and the pumping itself gets rigorous the longer into the life of a filter you get. Still, I see it as a necessary evil to get clean water – we can’t expect five-star luxury in an emergency situation right? To combat these limitations, MSR made sure that…

PRO – …Maintenance and upkeep is so darn easy

MSR included a few subtle features that make maintaining and caring for your Microfilter a breeze. The inlet hose included is a good length (over 1m), and provided is a float for the end. Think of it as a bobber for the end of the hose, that helps you keep from drawing excess dirt from the bottom of a pool of water, while also helping avoid that aforementioned surface contamination. When it comes time to clean your ceramic filter (which will come eventually and then frequently, I promise) MSR has provided a scrubbing pad that should take care of any undo clogging. Also provided is a gauge to determine when it’s time to replace your filter (nothing extravagant, just a plastic runner that, when slid along the filter too easily, mean that a new filter is needed). Everything also fits in a nice carrying bag that is also a nice spot for the instruction manual and maintenance directions.

CON – Weight

The MSR Microfilter checks in at 1.5 lbs. – which I found to be a pretty middling number when compared with other portable filters. When purchasing one for myself, I decided that the extra weight was worth it for the service it provided.

Sneaky PRO – Cost

I originally thought this could be a negative – sure, I did plant a bunch of money trees in my backyard, but the guy at the flea market I bought them from told me it’d be at least 3-4 years before they yielded anything. The more I thought about it though, the more comfortable I felt with the purchase. No longer do I need to cart water around with me when I have water sources present. Obviously if I don’t have any water access this is a different conversation, but in my neck of the woods this is a moot point. The pressure I can take off my mind (and back) made this well worth the investment.

One last point worth mentioning – filtration at 0.2 microns means that the MSR MiniWorks EX Microfilter will protect you against bacteria, protozoa, and will also filter particulate and other potentially harmful chemicals. It is not effective or meant to filter out viruses, so your ability to choose proper water sources when possible is clearly still necessary. You’ve gone through the trouble of putting together a Bug-Out Bag in the first place, I know you’re all responsible enough to take this into consideration!

Overall, I want to stress that there’s a reason you often won’t find this filter in stores because it’s sold out, or that it gets quality reviews wherever you read about it. From first-hand experience, I have no problem recommending the MSR MiniWorks EX Microfilter as a vital component of any Bug-Out Bag. While I have read and heard second-hand accounts of difficulty with the product, this a classic case of scratch my back and I’ll scratch yours. Take care of this Microfilter, and it will take care of you for years to come.



  1. Well this does sound like a great option.. pound for pound… and you are right.., if you are going to take the time to build a bag.. then might as well.. build it right.. and weight is a big topic! Thanks for the look! will be checking this out!

  2. Thanks Luke,

    Delay in replying here (getting married will do that!) but wanted to say thanks for your reply!

    On the market now is the MSR Hyperflow MicroFilter, which weighs even less (I think I read 9.5 oz.) and claims to pump faster than most filters on the market. I personally haven’t used this product yet and have read mixed reviews – if anyone stumbles across this and owns one, I’d love to hear an opinion!