Thanks benjammin, actually I do carry a MSR 10 liter dromedary bag and the bottle in my bob and pack but for shorter trips I just carry the bottle. I treat the water the same in either case with the combi and steripen and the combi filter will screw in the msr bag as well which is good.I thought about using a MIOX for the 10 litter bag but I can't stand the chlorine taste or the long dwell time, so it takes a little longer with the steripen at 32 oz a shot and I'm tired of Iodine.