Thanks for all your insights.

to clarify: No, I wouldn't even try to more a 30 gal barrel, it'd be for shelter in place.

I wonder if any leftover soda in the 2 liters would contaminate the water?

The idea of many containers -- redundant backups -- is a good one.

Teacher RO

PS My planning is as follows: 1 gal per person/per day ( plus a gallon a day for pets!) for a minimun of five days.