Yes, exactly on both accounts. That's the way I made mine, half-inch
increments, blue food coloring. Such a quick and easy, useful tool.

azsun99 wrote:
> A suggestion on the home-made manometer, is to mark the U on one side in half-inch
> increments, but number each as a whole inch. And I put green food coloring in the
> water to make it easier to see. And easier to stain everything when it sometimes blows
> out the other end when the gas is turned on :(.
> Worked for me.
> Jerry