Few bead questions that I can't seem to find answers for:

1. Amount of beads to use?
I have a desktop 20-25 cigar humidor. Nothing fancy...how much bead-age should be used? I bought a half pound (8oz) bag, and currently I have 1oz of beads in there. Is this too much? Too little?

2. Amount of water?
It says to spritz till 70% are covered....how exact is that? If I'm off a little one way or the other, will I kill my smokes?

Thanx,
Louie