A lot of these guys on here are from SW Ohio. We don't get too much chatter from the guys in central Ohio.
To give a very vague answer to your post since I don't fish either of those lakes I would think you could catch crappie at either lake 8-15' deep. This is a general depth and probably applies to most lakes. I'm not sure why it happens but in Sept for a few week period I will start catching fish down to 20' and deeper. After a few weeks the fish will generally start moving shallower again.
I hope this helps.