Anyone know if you can seal tap water in it and bring it to a low boil to sterilize it for storage, assuming you leave around two extra inches of unfilled bag below the top seal?
I doubt that this is an option. The vacuum will suck out the air and water to the back of the unit.
Leaving this isssue aside, just sealing without the vacuum is tough because the sealer seals with the bag on its side. Water will have a nasty tendency to spill.
I have had success with freezing stew before sealing so I suppose you could seal non-sterile ice in bags that are suitable for sous-vide.
Conway Yee