MSR Miox

Compared to water filters, this thing is a leap forward. It's the size of a sharpie marker, so the weight and size are worth it alone. It's very easy to use, and eliminates the issues with pumps and filters.



If you are looking to replace or upgrade a pump or filter, get this now. You won't be disappointed.

Once you get the hang of it, it is a piece of cake, pretty fast, and it has done well for me. Very lightweight, and it treats even cloudy water. No filters, just batteries and salt.

I got it because it was very small. It does a bang up job of treating water, and there is no taste that I can discern. The only problem is that you have to wait a little while if you want to well and truly kill everything like Cryptosporidium. This isn't a big deal though. If you treat all your Nalgenes / Camelbaks before bed, you're golden for the morning, and as you finish one off during the day, refill and treat it and by the time you get to it again it's ready to go.

When I first got it, it worked like a charm and I used it quite a bit. The most intensive test was a 2 week trip in Canada where we used it to purfy water for up to 8-10 people. It pretty much worked flawlessly and gave pretty good battery life.

Then came last year. My first overnight outing in 2006 was to the Maroon Bells to climb the Bell Cord. I arrived early to get a camp site and decided to purify a bunch of water for the group. I had a terrible time getting the MIOX to work - it would repeatedly give me a "low salt" indication on the LED's. I thought maybe the battery was low (though the battery LED didn't say so) so I replaced the battery. Not much change. I'd have to re-fill or shake the unit multiple times to get one batch of treatment fluid. Plus it burned through batteries MUCH faster than in the past. I think we ended up using Aqua Mira or someone else's Hiker filter for the rest of the trip.

I came home and tested the unit in the kitchen with pretty much the same problems. I called MSR who said I could send it in and they'd look at it, but we were leaving for Peru in about 2 weeks. I reserached on the web and found that water retention in the upper, salt chamber was a known problem. Supposedly, newer models had fixed this problem so, since we had little time before our trip, I just went out and bought what I assumed to be a newer model.

Long story short, I had pretty much the same problem throughout the Peru trip and eventually went to using the filter and/or Aqua Mira for the rest of the trip.

The websites had also related a procedure for making sure that all the water drains out of the salt compartment into the treatment cell, but it's a huge PITA and didn't work consistently either. Most alarmingly, several times the unit would appear to work (i.e. no warning LED's) but from experience I knew that it hadn't run NEARLY long enough to properly oxidize the brine solution (1 - 2 seconds vs. 20 - 30 seconds).

SOOO... right now I'm not sure what to say. I'd had more than enough tent nights for the year by the time we got back from Peru, so didn't have an occasion to try it again once we got back.

Bottom line is that it worked flawlessly for me for over a year (including many weeks of twice-daily use), then pretty much stopped working altogether (i.e. it "works" but is almost impossible to get it to properly complete even one treatment cycle). A replacement unit had pretty much the same problem.

My current guess is that it has major problems when it's even a tiny bit cold outside. I was so disgusted with the unit by the time we got back, that I haven't even bothered to do any more research or get back in touch with MSR. I will probably do some more research here shortly and/or contact MSR.

I have played with this water treatment unit and I take no issue with comments about the functionality of it in producing a disinfectant for water. However it is really doing nothing other than that (a treatment process that can be easily duplicated with iodine or chlorine with much less weight and dependence on batteries and salt). It does not filter the water at all so in especially turbid water the floating particles provide a safe haven for pathogens to hide from the disinfectant. If you don’t intend to filter your water I would suggest saving time and money and bringing a few tablets along. If you want to truly reduce the turbidity (and increased risk of pathogens associated) I would suggest using a true filter. This technology was originally produced for the military to disinfect large volumes of water at once and I believe MSR is simply trying to “create” a market for it in the outdoor community.

I got the Miox as a Xmas gift and was later shocked to learn how much it costs. Cost is a big disadvantage. Plus, it takes a while to get used to using it what with having to shake it, using the activation button to indicate the volume of water you are treating and using the test strips and making sure the strips turn the right color. I noted that the instruction manual lists FOURTEEN essentials steps for treating water with this filter. Big bucks and a multitude of steps to use the device properly is not my idea of an enticing piece of outdoor gear.

Its one advantage is size. The unit is not much bigger than a magic marker, although you also have the salt and a tube of test strips to go along with it.