it is definitely fine to use Same ratio. We only recommend eggshell powder because it is easier to get, and is only used on a temporary basis.
Ferrets: Contessa Kitties: Watson, Oskar DIP Sinnead, Vincent, Boris, Zeus and Athena, Willow, Mr. Frodo, Indie, Lucrezia, Judge, Odin, Miss Emily, Suki, Cody, Aristotle, Butterscotch, Frankenfurter. RIP Herne, Ligeia, and Mr. Stubbs
Human grade bone meal has more nutrients than egg shell powder so its a better choice, but egg shell is easier to get. any bone meal should be good, i hear the NOW brand bone meal has been mentioned a lot.