I had my mom pick up some grit for my Pigeons but she thought that I wanted grit for my Cockatiel but I don't give my Cockatiel grit so I have a bag of grit that I can't use. It has the regular small bird grit with oyster shell, red pigeon grit and charcoal mixed in. Would this be ok to give my chicks? Also how old should the chicks be before I give them grit? Also I raise Lobster Roaches and wondered if I can feed these to my chicks.