I don't know - she is in lock-down.
I just put the whole thing in there with most of the backing removed. Jordtim eats as much as he needs,
Like PridgNYC, I tossed it in and assumed (bad word) she knew what she needed. Sometimes she would chomp away for a few days, ignore it for awhile, and then chomp again a few weeks later
Like Wasabi, I was afraid I was giving her too much, so I stopped putting it in...result: not enough calcium.
So....
Do they kind of know when they do and don't need it? If so, is just leaving a cuttle bone floating around at all times the way to go?