Humidor humidity level.

My traveler is inalready! But unfortunately the foam that is supposed to stick the sponge (like thing) messed up so I figured I'd just let it rest on the bottom. I've checked it for a leak with the dropping the lid method and got good results, I was wondering if our shipboard water would be acceptable as well as bottled water since out water is drawn infromthe ocean and purified on the ship, without flouride. Also I don't have a gage for the humidity, are there any tricks to knowing if the humidifier is about right without a Gage?