I advocate opening any and all "new" to me bottles, be it new or used, if I havent checked it before, I will now....and as stated EMPTY. I had a new bottle with chunks of some kind of epoxy or sealant in the bottom that had got into the screen clogging it up and could have cost me more. Used ones just the same. Besides, you check it when you get it, and you wont have to worry if the tube is loose. Nothing to it really, ensure bottles empty, unscrew valve, gently pull (dont want to yank it out and tweak the siphon tube), tilt upside down to remove debris (or spray air in it making sure eyes are protected) check siphon, reinsert with thread sealant on valve threads, tighten and enjoy piece of mind.