MSR HyperFlow Microfilter

I used this filter over six months of almost weekly backpacking but only in flowing water. Filtered 16 liters of snow melt for our climbing party of 12 in less than 30 minutes and hassle-free. The bottle-mount adapter fit most of the 1 liter bottles carried by our team. Fast and easy to use.

I just returned from a 7 day trip to the Sky Lakes Wilderness in Southern Oregon. Three of us had purchased MSR Hyperflow filters for the trip. We are all planning on returning them. Each of us had done some brief testing at home and all seemed well, but in the field all three were almost useless by the end of the week. One failed on the first day. It pumped 3 or 4 liters as advertised, but quickly became very hard to pump. It was back flushed, but this didn't help. It could be used, but took a lot of pressure to pump and was very slow. The other two filters experienced similar problems throughout the week. We back flushed frequently, but the Hyperflows were all extremely hard to pump, and therefore very slow.

The filter element seems far too fragile for backcountry use. It can't be frozen, and requires a lot of care. It is too bad because I love the design of this filter. It is compact and lighter than any other filter I have owned. Until the filter element is re-designed, I would not recommend this filter to anyone.