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Keep your water clean for years.

Filter your water year after year with the MSR MiniWorks Ex Water Filter. Clean this lightweight, compact filter back to like-new condition, without any disassembly tools. The MiniWorks ceramic element ensures long-lasting protection against bacteria, protozoa (including crypto and giardia), and particulate, and the carbon core removes yucky tastes. MSR's little wonder (7.5 x 2.75in) can filter up to 1 liter per minute. As a bonus, the MiniWorks Ex Water Filter screws onto a standard Nalgene bottle or any MSR dromedary bag. *Kit includes stuff sack, hose float, scrub pad, and instructions.

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MSR MiniWorks Ex Water Filter

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Here's what others have to say...

After reading the reviews, I'm convinced this is a high quality, durable filter. I first encountered this filter when hiking in Nepal with some Finnish friends. They used the filter, then used a UV filter on that water. I didn't exactly understand why; something about the MSR being able to filter out something, and the UV being able to filter out something else.
I would like to ask you guys if this MSR filter is sufficient for pretty nasty water that may have giardia inducing parasites, etc.? Or do you typically use this filter COMBINED with another purifying device like UV or drops?
I understand that it probably depends on the water source, but thanks for any help.

Responded on

Hey Max,

So this is a great filter. I've had this filter since around 2008 and as long as I clean the filter and store it properly after each use, it will continue to last me for years to come.

It has an inner charcoal filter (for tastes and odors) and an other ceramic filter that filters out particles above 0.2 microns in size. So that is almost everything. The one thing this does not filter out are viruses. This is why you saw those people using the UV light (most likely a SteriPen) as a final step to kill any viruses that could be in the water source. Personally I'm not a huge fan on the UV pens as they do not kill everything in the water as there are certain parts of the water that do not come in contact with the UV light.

An alternative to the UV lights (SteriPens) are tablets such as (Item # CAS0775). The tablets meet EPA purifier standards for the neutralization of viruses, protozoa, bacteria and giardia cysts. So those will work great for treating your water. Only down fall is there is a 30 minute wait time after putting the tablets in the water and then there can be a bit of an odd taste to the water.

Shoot me an email if you have any questions at all!

Jared D.
Expert Gearhead

5 5

a workhorse

  • Familiarity: I've put it through the wringer

Built solid, this thing is definitely designed with durability in mind. And even if something were to break, it can be taken apart in the field without tools. Literally every moving part is easily accessible. I feel like the only thing that could potentially break, the pin that makes the lever hinge, can be easily replaced with almost anything.

The flowrate is pretty good, it's definitely not as fast or easy as a gravity system. But my understanding is that this filter is more effective anyways. Screwing the nalgene bottle to the bottom makes filling up a breeze. It takes about 2 minutes to fill a nalgene.

Not bad for something that I bought over 10 years ago! Just makes sure you keep the ceramic clean, and grease up the o-rings (make sure it's food safe of course) and this thing will last a really long time.

5 5

Reliable and field friendly

  • Familiarity: I've put it through the wringer

This is a great reliable water filter that's easy to use and easy to clean while on the trail.

Unanswered Question

I bought one of these a while back and struggled to get it to pump any water through. Not sure if there is a manufactured defect or if I failed to prime it correctly. The priming instructions that come with it are a bit vague. Any tips/more detailed instructions on how to go about priming it correctly and what I should be looking for to determine if I primed it correctly? Thanks.

5 5

Germaphobe love

  • Familiarity: I've used it several times

water. The ceramic filter is replaceable which is nice. and the 2 micron size filter will take 99.9 % of everything out aside from viruses (just use the purifier drops) It is simply a reliable work horse. I love it. I even use it at home sometimes just because!!

5 5

So far I like it

  • Familiarity: I've used it once or twice and have initial impressions

Used the MSR on a 3 day hike in a Gorge (plenty of flowing water) In the past I was skeptical of tablets so this caught my interest. i also plan to use it for having drinking water for off grid purposes. It's very convenient to use and I found it weighs slightly over 1 lb by about two ounces.

5 5

Just great!

  • Familiarity: I've used it several times

Easy to use, and fits a wide mouth Nalgene bottle, as well as the MSR hydration bladders.

5 5

My favorite

  • Familiarity: I've put it through the wringer

I've owned the three different water filters and this one is my favorite. I like the ergonomics with how it pumps water and I like the fact that it screws to a nalgene bottle. Whatever model of water filter you get, try to avoid getting one that pumps up-and-down because it will eventually become a burden.

5 5

Great and still going strong

  • Familiarity: I've put it through the wringer

I've had this filter for about 3 years now and it's still working strong for me. It's simple to use, easy to clean in the field, and works quickly. I appreciate that it screws onto a Nalgene bottle.

This filter is just what you want for a long trip or even just a long day trek.

3 5

Impressive in the field

  • Familiarity: I've used it once or twice and have initial impressions

Took this pump with me and two buddies to Vermont for backcountry, mountain backpacking.

Pros: Easy to disassemble for maintenance, water quality after treatment is fantastic, ceramic filter can be replaced.
Cons: Lighter options exist, must be cleaned and dried daily - it will clog if not taken care of.

Only three stars because if you can't clean it (Buddy #1 lost the cleaning pad) it will clog, and you will be super glad that you brought some Aquamira.

5 5

Great Overall Filter

  • Familiarity: I've used it several times

After using this pump on a few trips I have come to love it. The ceramic filter does a great job of filtering out everything. The carbon core does a great job of making the water tasteless. I have come to love the ability to screw you wide mouth Nalgene or Camelbak bottle onto the bottom of the pump. My only grip so far has to be there pump speed. It doesn't filter water very quickly; however, it seems to be a trade off for the durable ceramic filter. This pump is super easy to maintain in the field. It is easy to clean the filter to restore your pump rate. It is also easy to take apart and maintain with no tools required. All in all this is a solid pump for multiple day trips into the backcountry. Another solid product from MSR.

4 5

Pretty happy

  • Familiarity: I've put it through the wringer

I've used it for many trips here in VA over the last 4 years and have yet to see a real failure. Sure, if you're not careful or don't prefilter, then it will slow down faster then you might expect, but its also pretty easy to fix or maintain in the field. The vast majority of the time, all you need to do is pull the filter, scrub the outer layer off, give it a little rinse, and get back to it. How do I rinse it if I need the filter to get clean water? Even heavily clogged I've been able to get enough water to clean it in a few(ish) minutes. What if I forget the little scrub pad? In an emergency I've used a t-shirt to remove the dirt (not ideal I know, but it worked). The only other work I've ever had to do required no tools, only boiling water and vaseline. Its a reasonable price given the filter market and its given me nothing but clean water, though at not quite the advertised speed.

How do these filters work with sea...

How do these filters work with sea water?

Best Answer Responded on

No, unfortunately it will not. The ceramic element is so molecularly "huge" compared to even viruses that it will most definitely not remove sodium ions, which are wayyyy smaller. The carbon filter may help with a lot of solids and even some minerals, but once things are well dissolved in water, the carbon won't do much.

Bottom line, it will be good for gargling but not drinking.

You would need a desalinator to make it drinkable, and those will run you ~250 to upwards of 2,000. (google Katadyn Survivor 35 and 06).

5 5

Top notch

  • Familiarity: I've put it through the wringer

Love this filter. Used it extensively (trail/wilderness crew tested). A little heavier compared to some other options, and maybe even a little slower overall, but the maintainability with the ceramic filter is awesome. I definitely scrub the filter quite often, but have only had to replace the filter once in 8 years. I've seen some other paper filter systems pump faster, but it's hard to give them a deep scrub and you end up replacing the filter a lot more often (and spending $$'s). Maybe not an option for the gram counter, but a good option for those who like a dependable and durable treatment system.

5 5

A wonderful Filter

  • Familiarity: I've put it through the wringer

Hey, I bought one of these when they first came out.. and I have loved it ever since. I bought this new one because I thought it was small but it want not; so I gave my old one to one of the new members of our hiking group. I am super happy with this just like the old one I had. I once had to filter a puddle of clear looking water about 6" deep and it work like a champ. I added chemical treatment to that as well. I do remember that the water tasted like slime but it was clean. lol

5 5

Long lasting

This is an expedition-level water filter, and because it is field-serviceable, you can keep the performance level high pretty much indefinitely. I have used mine all over the Rockies, and as far away as the Himalaya, where not having one would have been a crummy situation. Does require occasional maintenance to maintain performance, but rewards you with durability and great tasting water.

5 5

Trustworthy and tough, awesome filter!

  • Familiarity: I've put it through the wringer

I bought this filter 7 or 8 years ago and the fact that MSR still makes them is reason enough to understand how great they are. I've had mine over about 40 peaks and across the country. I've only had to replace the filter once, because it got broken in my luggage on my way to mexico (note to self: don't use in Mexican water with a cracked filter...) but this filter isn't the smallest, lightest or fastest, but it's crazy trustworthy and produces great water from practically any source. I love this filter and would highly recommend it to any one. the picture shows the size of the carry sack.

Trustworthy and tough, awesome filter!
Responded on

Hi Mager,
I have this filter, but it has sat unused for about 7 or 8 years now. It wasn't ever used extensively, but I am planning a trip and would like to bring it. Any tips to make sure the filter is still ok? Thanks!

Responded on

sorry i didn't see this earlier Chris, i would just lube up the o-rings with some vasoline and probably run some tap water through the filter just to re-familiarize yourself with it