May I refer you to this posting for what I am about to explain.
After further refinement I find this “system” to perform excellently. I updated the collection bag (green in the pic) to include a sewn in 5 micron pre filter. I purchased the material from globalfiltercorp.com (Type Fiber, Micron Rating – 5, Bag Finish – Plain, Bag Size – 1, Bag Style – PESS) but I think you can buy this on line.
I use this system exclusively when I backpack with my four grand children. The filter works flawlessly and produced water from the .02 micron filter quickly and in large amounts. On a nine day trip this year with the young one I did NOT need to back flush the filter and the filtering rate did not slow substantially…..I did not quantify flow rates so I do not know exact differences if any. (I did bring a large 60 ml syringe for back flushing if needed.) Total weight of the system [SAWYER WATER PURIFIER (.02 micron) (8.75oz WET /FLUSHING SYRINGE (1.12oz)/ BAG, (5 micron) prefilter&HOSE (4.26oz)/BAG (.35oz)] – TOTAL 14.7 oz. While the system does not fall within what you would call a “light” water treatment method, as compared to chemical or UV technology, it does provide water in large amounts that are virus free in little or no time.
