I agree, I keep an empty nalgene bottle in each of the survival kits as well as the 72 hour bag. I actually keep water in the nalgene bottles that are my in the pack that I refer to as my "Rescue Pack." I change the water out often.
Some military redundancy rules are hard to break for me. I have my filter and water purification tablets.
I got out of the Army in 2008 and don't recall LRP meals. What are they?