Convert to the Micropur tabs that come in the individual foil packets? They may not be as space-efficient, but they're pre-sealed and taste better.

I believe Potable Aqua (iodine) has a shelf life of 5 years. I just bought some Potable Aqua (chlorine) with an expiration date of 12/09 but I don't know how old they are. I am in the process of replacing all the iodine tablets with chlorine anyway.

Wow, someone dug deep. Consider this closed, guys.

5 years in factory packaging. After that, 6 months. Might be good longer, but this something where you want to err on the side of caution.

Ame, check everything in there that is metal. Carefully. I've given up the repacks- I can't carry as many chlorine dioxide tablets, and I have to let the water air out for a while to drink it, but they make things so much easier.