I think you are on the right track. One thing Oldranger brought up that you might not be aware of (perhaps you do, but I don't know your experience) is the color of your urine. It should be 'clear and copious'. If your not urinating, your not drinking enough. I have a difficult time with remembering to drink, drink, drink.
We make a habit of drinking 1 liter before we even take off (we call it cameling up). We think of crazy things to drink a toast to and it kind of sets the mood for the day. There's a joke about 'hydrate' and 'dehydrate'....I'm sure you can figure it out (see the movie Jarhead).