Purchased the gravity flow about two years ago... Works flawlessly. Ive filtered extremely dirty water and have never had problems with flow rate. When flow decreases a quick back flush is all it takes. When with larger parties having the ability to filter 4L and carry back 4L more in the dirty reservoir is awesome. Two thumbs up!!!
Purchased the gravity works about two years ago.... Absolutely no complaints. Maintains great flow even filtering extremely dirty water. When flow does slow a bit, a quick back flush is all it takes. I use it for backpacking/camping. With bigger parties having the ability to filter 4L and carry back another 4L of dirty water is awesome. Also can double as a quick shower by removing the fliter :-)