Last year, Backpacking Light published a review of the MSR Hyperflow filter. It was one of their subscription-only articles, so I never read it. Apparently, the reviewer attempting to filter only slightly-less-than-clear water and experienced a very quick build-up of material in the filter element that could not be removed by back-flushing and vastly deteriorated the flow-rate of the filter. Since the review, MSR has acknowledged the problem and released a new filter cartridge to address the problem.
Yesterday, Backpacking Light published a second review of the Hyperflow, this one using the revised filter cartridge. The reviewer once again experienced the same problem, with only a slight improvement in the flow-rate of the filter once clogged.
I have had a MSR Hyperflow for a little under a year and have never experienced the clogging problem or the lack of effectiveness of back-flushing. I do tend to be judicial about selecting my water sources and filter the clearest water I can find, which may be why I have not experienced the reviewer’s problem. (In fact, I could probably get away without using any filtering on many of the water sources I choose, but I, like most, have been indoctrinated with the need to fear all wild water sources.)
What caught my eye in the second review was that MSR was offering free replacement filter cartridges to those who had filters manufactured prior to November, 2008. The cartridge is the most substantial component of the filter, and getting a new one is a bit like getting a whole new filter for free. This afternoon I called Cascade Designs (MSR’s parent company) at 1-800-531-9531, read them the serial number on my filter, and there is now a new filter cartridge in the mail for me! MSR customer service gets two thumbs up, even if there may be issues with the product.