Top critical review
3.0 out of 5 starsClogs on Tap Water, Do Your Research
Reviewed in the United States on June 12, 2024
Update: Sawyer eventually provided some tips, and after multiple hot soakings and backflushings the filter is working. Nothing I did prior to the clog was contrary to the instructions. Sawyer still recommends storing dry and doesn't mention flushing with distilled water. Bottom line, your filter kit will need to include lots of tricks and patience. Original review follows.
I know these are popular and I was excited about the light weight, but I got zero use from this filter before it failed. Mine slows to an unusable flow rate after about 1/4 cup of tap water, or even water from a reverse osmosis filter. Backflush per instructions and I can get another 1/4 cup before it stops. That's less clean water than you need to backflush the filter. Emailed Sawyer support 2 working days ago, crickets. Soaked in vinegar per internet tips, no luck. It's a total loss.
Apparently if you let this filter dry after flushing with anything but distilled water the minerals will clog the hollow fibers. Even with distilled water, it may not after dry storage and must be soaked before your trip. Some recommend storing it wet, so then you must use bleach to keep the bacteria under control. You won't find this info on Sawyer's web site. So if you plan to rely on this in the backcountry, do your research and have a backup plan. For now I'll go back to my heavy but reliable MSR ceramic filter.