I've been using gerber babymilk bags in my PSK for water storage. They hold up well, but they store significantly less than a liter of water, and most water purification tablets purify a liter at a time. If I have to, I'll cut the tablets into smaller pieces, but I'd rather not if I can help it-

I'm looking for a durable one liter water storage bag to fold up and store in a tobacco tin sized PSK. I've seen some storage bags that have a plastic cap, but these don't fold flat-

I do have a "just-in-case emergency water bag" that came in an automobile kit, it has one of those plastic locks that can be seen on bread (not the wire ties). This looks like it holds quite a bit more than one liter though (maybe 1.5 or so, it doesn't say anywhere).

Any recommendations?

Oven bag and a small binder clip. (The little black triangular do-hikies with the wire legs, for those who don't know the name.)

Although not the most appetizing choice, have you considered non-lubricated condoms?

According to SAS books, they work quite well, but part of me thinks, "How thirsty would I have to be..." <img src="/images/graemlins/crazy.gif" alt="" />

Yep, but this is easier to fill. Open it, stick it in the water, lift out, add water tablets, spin it, and clamp it with the binder clip. Give the tabs some time to work, and bob's your uncle.

One liter Ziploc brand freezer bags are quite leakproof and tough (the kind where you squeeze the seal together manually, not the kind with the convenient slider on top). Other brands are not always so good (I haven't tested many though). The ones with the sliders leak a little bit at the corner, though not enough to make them useless.

I think it's best to not completely fill ziploc bags, but instead leave a little bit of slosh space. However, I don't think anything bad happens if you use a 1 liter purification tablet in 0.9 liters of water.

Ain't killed me yet.

I've never been able to find a local source of non-lubricated condoms.

I used to carry a normal condom, but I found it took too much room for my small kits.

> I think it's best to not completely fill ziploc bags, but instead leave a little bit of slosh space.

With air in, I think you mean. Water isn't compressible, but air is and can absorb some of the force of a blow eg if you drop it.

I've been using 1L and 2L I.V. bags (emptied of expired saline). Tougher than all get out, but you either have to cut out the access ports or make a rig for filling.

I haven't been leaving air in the ziploc bags. Think of a really full bag and imagine poking at it with your hand (not with something sharp). The skin is under tension and the water can't move around in the bag, so the pressure increases and the bag may burst. Now do the same thing with a 3/4 full bag (no air space). The bag can easily change shape so I think it's less prone to breakage. The 1 liter bags are pretty hard to break. This is more of an issue for the 1 gallon ones.

I notice these bags aren't as easy to find as before, and they don't come in as many sizes as they used to (haven't seen 1/2 gallon or 2 gallon ones lately). Maybe I'll stash away a couple boxes.