I couldnt find any how to’s online on making a gravity system with an msr hypflow, so i just went ahead and whipped one up. The bag is made from a $10 wal mart backpacking tarp, 1.5″ grosgrain around the rim and for the handles and a few pipe fittings to connect everything. The fitting connecting the filter cartridge to the bag is a 1/2″ threaded female to 3/4″ pvc. The retaining ring is a piece cut off the end of a 3/4″ elbow. Silicone to seal it all up. Not to shabby. Slow flow rate, but better than my original frontier pro mock up i did with a plastic bag and the top to a smart water bottle. Hoping that a backflush will improve flow rates. Will use a pre filter of some kind to minimize build up in the filter during extended use. I dont see myself using this often, but thought it might be good for a group trip where someone else was carrying a steripen. Enjoy!
Thomas
