Our chicks will be 7 weeks old in two days, we've been mixing in chick grit with the food, but they need to move to the #3 grit (I have the Cherrystone grit) so I put some of that out free choice today. They went to town on it and I'm afraid they are eating too much of it. Should I take it away for a bit or leave them with it free choice? Do I have to worry if they will eat too much of it? They are kind of bored right now as they are stuck in the coop until we are done making the run hopefully in a couple weeks. They get a little supplemental food besides the starter/grower but not too much.