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MSR Miniworks filters very slow
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Wyatt Gross
MSR Miniworks filters very slow on 05/05/2013 14:47:53 MDT Print View

I have a MSR Miniworks and it seems to filter water very slow. I have only had the filter for about one year and always take great care of it after every use. I completely disassemble it, wipe it down, lube up the moving o-ring, boil the ceramic element and let air dry for a few days after every use. Even after all of this it takes about 5 minutes to filter one 32 ounce nalgene bottle worth of water. On top of this, the water I filter is never extremely dirty or muddy. I usually filter water from quick moving, relatively clear water. Is this a normal amount of time to filter that much water? If not, what could I do to help improve the speed of my filter? Thanks for your time and help!

Jon Fong
(jonfong) - F

Re: MSR Miniworks filters very slow on 05/05/2013 15:23:52 MDT Print View

have you tried cleaning the first?

Wyatt Gross
Yes on 05/05/2013 15:33:37 MDT Print View

yes, I clean it very thoroughly after each use (as described above) and it still continues to filter very slow. The first time that I used it was the only time that it actually filtered water at a pretty quick rate.

filter on 05/05/2013 15:39:10 MDT Print View

sounds like a normal filter to me.

replace the element and it will improve, for a very short period of time.

Not being sarcastic, just blunt.

You are citing the exact reason why so many avoid filters.

Edited by livingontheroad on 05/05/2013 15:40:24 MDT.

Jon Fong
(jonfong) - F

Re: Yes on 05/05/2013 15:40:16 MDT Print View

What do you clean your filter with? I use a scotch brite pad, as the ceramic fitler is a sacrificial element. You don't really clean the filter, you remove the outer layer of clogged ceramic. There is a gauge on the bottom of the lid that gives you an idea as to when the filter is worn down to low and need to be replaced. If you are doing this, and your flow is still low, it sounds like you have another problem. Best regards - Jon

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: MSR Miniworks filters very slow on 05/05/2013 15:46:55 MDT Print View

I've seen that kind of problem on an earlier model of MSR filter. Have you looked at the foam filter on the intake?

Years ago we had some really ickky raw water as our only water source, so we pumped it. After about one quart, the progress slowed down to nothing. We fooled with it, cleaned it, poured boiling water through it, and everything else, and it was still clogged somehow. This particular model had a top metal screen, a ceramic filter, and then a paper filter. We had to quit using it and boil our water, instead. After the trip, I took it apart and tried a few things. Once the paper element was removed, it worked perfectly. Why would that matter so much? Because the raw water had something oily in it, and that coated and blocked the paper element pores. Had we known, we could have simply removed the paper filter on the trip.

Your filter is not that complicated, but it might be something similarly easy to fix, like with the foam filter piece.


Wyatt Gross
Thanks on 05/05/2013 15:49:49 MDT Print View

Thank you for your help. I was just out with a buddy who uses the hyperflow and it filtered water about 10x as fast as my miniworks. Made me wonder if there was a flaw with my filter that would cause it to filter so slow. And I do scrub the element with a green scrub pad as well. Also I have only pumped about 5-10 gallons of water through it at most so dont really want to buy a new element. But thanks again for the help!

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: MSR Miniworks filters very slow on 05/05/2013 15:52:17 MDT Print View

Back in the old days, we used filters like that a lot, so we sometimes had to clean them. Even though the raw water looks almost pristine, there is stuff in there. After examining the nature of the stuff that was cleaned off the filter, I came to the conclusion that the stuff is microscopic in size. We found the best method was to gather up a bucket of raw water, and then let that stand/settle for a while. Some of the microscopic stuff will settle to the bottom of the bucket. Then filter/pump the raw water off the top of the bucket. See if that helps progress.

I know. When you are thirsty, you want to filter and drink the water immediately. Then you will have more clogging problems.


steven franchuk
Re: Thanks on 05/05/2013 16:20:36 MDT Print View

Only 2 possible cause. filter cartrdge is plugged. rub it agressively with the grean pade. You want to scrub of the outer layer of the sintered ceramic filter off (at least 1mm maybe more). Lightly scrubbing the filter with the green pad won't work. It requires an agressive scrub.

The second possible caause is the pressure releaf valve (a little rubber ball with a spring). When the filter gets clogged the pressure releaf valve will open on dump the high pressure water back into the water intake hose. If the valve is stuck open, leaks, or the spring is missing it will greatly reduce the pressure on the filter causing low filter speed.

The only other thing I can think of is hard water minerals. hard water buildup in the filter will plug it and if that is the case even a very very agressive scrubb may not fix it. If that is the case the only solution is to replace the filter cartridge. however I don't think one year of use is enough time for hard water to be an issue.

I got years of use on the origninal filter without any significant issues. Still works although I now use a Sawyer in line filter.

Edited by Surf on 05/05/2013 16:30:36 MDT.

Jon Fong
(jonfong) - F

Re: Re: Thanks on 05/05/2013 16:41:04 MDT Print View

FYI, they replaced the ball check valve with a duck bill valve. I recently go "somewhing" stuck in the duck bill valve and pumping went to hell. The pump would blow back water out of the cylinder into the inlet tube. The cyclinder would fill half way with air and the pump flowrate droped to 1/2. Once the duck bill valve was cleaned the pump worked fine. I contacted MSR trying to get the original ball check valve but is has been obsoleted. To bad - Jon

Wyatt Gross
duckbill on 05/05/2013 17:00:17 MDT Print View

The duck bill may be my problem then. I too get half air and half water on each stroke of the handle. I always clean the duckbill however, does it need to go back in the filter head a certain way?

Jon Fong
(jonfong) - F

Re: duckbill on 05/05/2013 17:08:34 MDT Print View

If I remember correctly, there is a spring that pushes against the base of the duckbill valve into the housing. The duck bill should point > with the apex facing into the main cylinder. When assembled correctly (and the main cylinder is primed), there should be very little air in the main chamber. Good Luck - Jon

Jake D
(JakeDatc) - F

Locale: Bristol,RI
Re: Re: MSR Miniworks filters very slow on 05/06/2013 06:42:44 MDT Print View

Also don't forget to prime it before you connect your water bottle. pump water through until all the air in the hose and "window" is replaced with water and it's flowing nice out of the bottom. then connect your bottle and fill.

Benjamin Auer
miniworks on 05/06/2013 08:31:47 MDT Print View

I had a miniworks for several years. I eventually got rid of it out of frustration. No matter what I did or how much I cleaned the filter it was slow, clogged easily, and not worth the trouble. I have switched to the sawyer squeeze when it is above freezing and just chlorine dioxide tablets if I am expecting temperatures below freezing.

(xeren) - F

Locale: Southern California
glacier water on 05/06/2013 11:10:35 MDT Print View

you're pumping clear water, but is it coming from a glacial source? anytime I used my miniworks in the sierras it would clog up from the particulates coming from glacier water- it's why I sold mine and replaced it with a platypus gravity works filter. I'm able to clean water for 8 people in the time it used to take me to do it for 2.

Edited by xeren on 05/06/2013 11:20:03 MDT.

USA Duane Hall
(hikerduane) - F

Locale: Extreme northern Sierra Nevada
MSR Miniworks filters very slow on 05/06/2013 11:29:20 MDT Print View

Aren't they slow anyway with being so small?

Sumi Wada
(DetroitTigerFan) - F

Locale: Ann Arbor
Re: MSR Miniworks filters very slow on 05/06/2013 14:46:23 MDT Print View

Call MSR. Miniworks is big and slow but not *that* slow and usually pretty easy to field-service. Something's not right. I had a problem with an old Sweetwater, called MSR and their customer service was great (they asked me to send it in and they replaced it.)