User Review: MSR SweetWater Purifier System
Ok, I have used this pump on prolly around 15 full week long trips. The action of pumping is great you could no ask for anything better, and it pumps at a fast rate.
Personally I have never had a real problem with it. However I have been told (from reliable sources) that when this filter is used in water with a high amounts of silts and clays it tends to clog the filter up.
There is a couple of easy solutions. If you wrap the intake peace that sucks the water up in a coffee filter it will help to stain the particles out. Also, if you put the cartridge into boiling watter and boil it, it will help unclog the filter.
I really think this is a great filter for most people. It's a great price and works well.