The milky white bottles (like milk comes in) simply do not last very long. I don't know why. But water stored in these containers tends to eventually leak out, even if you buy the water in them, store them upright, and they've never been opened. You go out to your storage area, and you'll find empty or partially-empty collapsed containers.

The clear plastic bottles store far longer. Just be sure to wash them thoroughly if juice or something came in them. Soak with soapy water and rinse very well. Trying to hurry this step could be counter-productive when you need it.

Glass is very stable, but I wouldn't recommend them in earthquake areas for obvious reasons.

And I wouldn't bother adding anything to the water for storage. If your tap water is good enough to drink, it's good enough to store. As mentioned above, keep it in the dark. And I store mine low -- they might bounce after falling 18", but they're not going to bounce from four or five feet.

Chlorine is safe enough for purifying water contaminated with organic materials (after filtering out chunks), but I would keep it tightly sealed for specific use when and where you need it. It outgases, so investing in a fresh supply every six months would be cheap enough.

Sue