I have 9 week olds and 3 week old chick and i will be putting them out in the shed tomorrow and were wondering once the older ones are 10 weeks old they're supposed to be fed Chicken Grit. But the little ones are supposed to have Chick grit. We have both but they all would have access to the grit. I but the grit at Tractor Supply. 1. Should we just feed them all chick grit until the little ones are old enough for the adult grit? 2. or should we find a way to separate the grit? 3. Could i feed the 9 week olds the Chicken grit since they're basically 10 weeks old?