MSR HyperFlow Microfilter

"Let me begin by saying the poor reviews are not to be believed... I have owned my filter for over a year and it is possibly the best filter i have used (I also own the minworks which has worked for years). All the poor reviews really took me by surprise and I suspect that they never properly back flushed the filter, if you get air trapped in the filter or flip the one way valves improperly (such that they invert when pumped) the pump will not function. These new filters are sensitive to air in the pumping and extreme cold. Overall it is fast and lightweight. My son's scout troop took two of these this summer on their high adventure and they worked like a charm, even the cleaning cycle was easy and straight-forward. My only qualm is how easy it may be to lose pieces, but if you are careful this is no problem."

"I just got done hiking the Appalachian Trail, and carried the Hyperflow from Troutdale, Virginia to Maine. (about 1700 miles) I hated every minute I had to use this awful pump. I was replacing an older MSR miniworks, which was twice the weight and moved a very low volume of water. Because of the way I had my water system set up with a camelbak inside my pack that is very difficult to remove on a regular basis, I needed some sort of pump to pump water in through the drink tube.The technology behind this filter is flawed. Simply stated, backflushing does almost nothing to clear this filter once it gets clogged. So you basically have a very effective, as-advertised 3LPM pump that is even exciting to use, until it clogs for the first time. That first time for me was about 8 Liters. After that, it was the biggest pain in the butt to use this thing. The pumping became so hard that I would need to brace one arm against my knee to get the needed leverage. It was like a daily workout, and I dredded pumping water so much that I ended up skipping water sources and at times running out of water all together.No amount of "backflushing" would restore this thing to its advertised functionality. In fact, once the filter gets too clogged, the backflushing method does not work at all because you are basically relying on a vacuum to pull the water through the filter during a backflush, and that simply is not enough psi to do the job. (the same pressure that I needed to brace one arm against my knee to pump water through is required to pull water back out during a backflush via a vacuum). So, in the end the thing just gets worse and worse. I finally called MSR, and the freely offered to send out a new cartridge. This to me is evidence that they freely admit the problem. My new cartridge? Lasted for 5 Liters, and immediately was worse than my old one ever was.I knew dozens of hikers on the AT who had bought this thing, and NO ONE was still carrying it by the end. In other words, I was the only sucker. One hiker I knew who was carrying this piece of junk basically had MSR send a new cartridge to every town along the trail, before finally demanding a replacement Miniworks. Each [$]cartridge will last you a day tops before it needs replacing.I guess the upside to all of this is that you have yourself a great filter as long as you have the luxury of receiving a package from MSR every few days. If you do not have that luxury, then stay away from this product, which I believe is probably the worst filter ever made."

"Encountered a lot of negative reviews about the product prior to purchase. Checked with MSR and they indicated early filter production problems as the culprit. Filter worked great on a 6-day Grand Canyon trip and kept the 4 of us well hydrated. The water we pumped was largely silt-free. Brought along an MSR Sweetwater SiltStopper pre-filter just in case, but didn't need it. Followed the back-flushing recommendation after every 8 liters or so and had no issues. Reversing the check valves is not a big deal either contrary to some reviews. Avoid pumping air into the filter element prior to back-flushing though. If this happens you need to return the check valves to normal operating mode and displace the air from the filter with water then return the valves to back-flushing position and back-flush. Can't beat the weight of this filter at less than 8 oz."

"I picked this critical piece of gear up few days before the trip [...] I did no research and read no reviews and decided to just try it.I took the filter to Desolation Wilderness. It performed extremely well out of the box. We drank running water, standing water and eventually, near Ralston Peak, really swampy water. Water tasted better then what I get at home! Nether I or my friend got sick. So filter did its jobs well.Filter is very simple to use and feels really distilled to only the parts you need. I was able to stick it in the cargo pocket of my hiking pants and mostly forget about it. Try that with one of the old style filters.However not all things are rosy:For example, it took me several hours of messing with it to really understand it completely after I came back from the trip. Switching it back and forth from back wash to regular mode is less then trivial until you just get it.The pre-filter is a great idea as it floats on the top of the surface of the water avoiding kicking up all the settled particles at the bottom of a puddle. However it often sucks in air as well and I found filtering was easier with two people.!Last but not least!Manual clearly says not to take this filter below freezing temperatures. This is highly disappointing, although I understand exactly why this is. Water expands when it freezes so this process could rapture the little fragile tubes that do the actual filtering.This would be a show stopper if I did more snow camping, but since I do not, I think i can leave with this. No reason I can't get a heavier duty filter for winter but why cary a huge, one when you can have this sexy tool?"

"I researched many water filters and read many reviewers complaining about ceramic filters clogging - even after just 100 oz of water (my camelbak, basically). The need to pull apart a ceramic filter in the field and scrub on it after so little water was not a plus; then there's the weight.



Then I came across this filter.



It's so simple to use, lightweight - and can be cleaned merely by backflushing with clean water (& in my experience it lasts long enough between cleanings it can be done at home).



While some worry about breaking or freezing, this is a tool - just like my GPS or camera; these things do need to be given care.



My final PLUS: While a ceramic filter eliminates everything, including taste - this gets rid of the waterborne nasties without getting rid of taste.



I swear there's nothing more appealing on a hike or camping trip, than tasting the water around you.



Without meaning to perhaps, the MSR Hyperflow Microfilter has added another element to my outdoor experience that I had never realized I was missing out on - taste!"

"I thought that I had done all of my research on this product before I bought it, but upon it's arrival I found some information in the provided literature that was not anywhere else that I had looked.

This filter uses a "hollow fiber" filter. This is exactly what it sounds like. When you look at the end on the filter, you see what looks like a bunch of the ends of tiny straws. The upside is that this filter filters well, pumps very easily, and pumps a lot of water fast. After reading the reviews, and doing my own research I was sold. When I got the filter, I noticed a little "warning" in the instructions that says you shouldn't let the filter freeze, or be stored below 0 deg Celsius. If this happens, The filter will be damaged, and may not filter out all the nasties that can make you so horribly ill. I can only deduce that as the filter is a bunch of tubes, that if it were to freeze, the resulting ice expansion would shatter the tubes. This seems like a major over site to me. I have been out ALOT when the morning dew was definately morning frost. So, I really have to wonder if on the next morning I wake up like that, I will also get to wake up to a busted water filter.

The instructions also relate that a drop from as little as .9 meters can damage the filter resulting in nasties in your water again.

With all that said, it really is a joy to use. It pumps really fast, and is well designed other that the obviously delicate filter. I'm still taking it out this season, but I'm bringing extra treatment tabs, just in case."

"Comments about the negatives listed on other reviews:

1. It did become much harder to pump and backflushing helped only minimally.

2. Backflushing can become confusing to make work - I kept pulling a vacuum at first. Think I have it down now.

3. Pre-filter is not good at all. I put the acorn pre-filter from my PUR Hiker on (now called Katadyn I think)and it is far easier now.

4. The "small" clean cover doesn't seem like much of a problem to me - when you take it off just stick it in the bag and you won't lose it. The check valves also don't seem like that big a deal either. If I can keep up with a quarter to open a bear can for a week surely I can keep up with these.

5. Compatability with non-Nalgene systems. This isn't an issue at all for me. I use two 1.5 liter consumer bottles from any grocery store. I can easily hold the filter above the opening with two fingers and thumb and wrap the other two fingers around the bottleneck. I find this much easier than creating ways to stand up bottles for a hose to go into.

Comments about the positives:

1. Size and weight are absolutely great. Unbeatable for backpacking.

2. Water tasted great - my old PUR always had a bit of a "kick". My buddy has the Katadyn version and it does too. We filtered for each other frequently on a recent Yosemite trip and the taste left no doubt which filter was used each time.

3. Started out very fast but due to it becoming difficult to pump it is only marginally faster than the PUR now. I am disappointed in this, but in honesty my PUR is also difficult to pump now and so is my buddy's. In fact, when using his on this recent trip I found it about like going to the gym.

Overall I like this filter - light, compact, water tastes great. I have used it on several weekend trips (north GA) and a weeklong trip (Yosemite). Really my biggest frustration is that is has become relatively hard to pump. I didn't carry a backup in Yosemite because my buddy had one but for the next few trips locally I'll probably take my PUR just in case. As long as the Hyperflow doesn't further increase in difficulty I'll keep it. But if it does, I'll take it back. At this point I'd recommend it, but with the above caveats."

"Please note that MSR is replacing hollow fiber filter cartridges dated before Nov 11th because of the clogging issue you have read in most of these reviews. You can call MSR and they will send you out a new filter. (Please have the filter element handy as we will ask for the serial number for our records and manufacture date verification)



My first hyperflow clogged up after 6 or so liters filtered on a backpacking trip in northern MN. After my trip I did exchange it for a new one. Spend 7 days in Glacier and it worked like a charm although the water was much cleaner in glacier. I did also order a replacement and do not have a review on the new cartridge.



This filter is very fast and light. Packs tight and is easy to take apart."

"On the 1st day of my backpacking trip I filtered clean running water with this filter and it worked great. The 2nd day of the trip I stopped to filter and the MSR Hyperflow was super hard to pump so I tried to backflush with the small amount of water I had left with no luck at all. We ended up boiling water for the rest of the trip and bad mouthing MSR for it. When I returned home I eventually got the filter to backflush which is a pain. The MSR Hyperflow does not pump as easy as it did when it was NEW. The documentation recamends taking a extra cartrige on longer trips, from my experience that means 2 days!

I'm not sure about the freezing, shake it dry. Dropping it?? It's a little weak but it is LIGHT.

I'll keep tring it and backflush the filter everytime, it takes time so that kills the super fast pumping time.

I knew it was too good to be true!"

"Right out of the box and into the water this filter requires little prep. Light weight and compact, perfect for fast packing or adventure racers who don't fully trust or like chemical treatment. Pumps well, and with little effort can fill a camelback in no time. Not a fan of the bottle attachment, so I just put a small piece of hose on the outlet valve to minimize spill, and pumped away! Water quality was good, but this is more of a selection of water source than the pump itself. The prefilter likes to float around so air suck can be a problem, but a little thought and some small rocks can help with this problem. A great little pump!"