I tested some bagel freezer bags from my local deli, but they leaked. Drat. They were a nice size, being close to the diameter of a 1 quart soda bottle, and made it easy to estimate volume.

There's another thing I never thought to practice... When I'm mixing up a batch of potable water in my oven bag or condom or whatever, do I know what a quart looks like in that container? I have to know in order to add the right amount of purifying agent.

After the bagel bag failure, I dropped by a pet store and wheedled a couple of fish transfer bags out of them. These seem great. Maybe not as robust as the cooking bags, but much closer to the right size. They occupy a smaller volume for sure.

Bear

i use 1 Liter ziploc bags and aquaclear tablets ( 1 tablet for a liter ) if i fulled it to the top i will know i got one liter <img src="images/graemlins/grin.gif" alt="" /> just throw in a tab per filled bag and i got the right dose. ( thinks of K.I.S.S. )
you could also mark the bags, full one liter in it and put a line of that water level ( on the outside ) and repeat it at the second liter level, etc. if you got a large bag...

dchinell,

FWIW, in on of the relatively recent (last month or so) threads, I saw a reference that someone had made to counting how many Altoid tins (base portion) filled with water it took to make a quart or liter.

Hmmm ... for the aggravation of looking it up, it would probably be just as easy to test it out by doing a bit of kitchen experimenting. Besides, think of what the spouse would say the next day .... "would you belive... him at his age, standing at the sink last night, just pouring water from a square can in to a condom? <img src="images/graemlins/blush.gif" alt="" /> And then counting the whole while". Perhaps the search IS a better idea huh? <img src="images/graemlins/crazy.gif" alt="" />