I would not use the oyster shell for chicks. Excess calcium suopposedly has the potentially to damage an internal organ. It doesn't happen all the time but supposedly it has the potential. I can never remember if it is the liver or the kidneys. I have no idea on using the charcoal.
I gave mine sand to use as grit. I just scooped it up from a pile I had from where mortar was mixed.
Now I am also confused on this. I found the grit for chicks at my local feed store, but a lot of people on here have told me not to give them grit if you are just feeding them the chick starter feed. They say only to give grit if you are going to give them treats like greens and such. I had previously read somewhere to give them grit regardless because when they are in a brooder and not free ranging they don't get the grit they need. So I am at a complete loss on this one, and I have stoped giving them any grit for now. I would ask your local feed store if they have a special chick grit, because I have not ever seen it at TSC. Sorry I proab just confused you also, just don't know what to do.
If all they are eating is the chick starter, you do not absolutely have to give them grit. If they eat treats or anything else, they have to have grit.
I started giving mine sand from outside the third day I had them. They were 5 days old then. I did not start giving them treats or anything other than starter until they were 3 weeks old. The reasons I gave them grit was, first, to get them used to eating grit. Second, I don't know when a bug may wander into their brooder. They may ingest a chunk of something they need to grind up, like a piece of bedding. I cannot see how giving them grit will hurt them. I can see how not giving them grit might hurt them. Many people raise chicks on wood shavings, feed them nothing but starter, never give grit, and never have problems. It is personal preference.
The last time I was at TSC, I saw chick grit. That is the first time I have seen it there. It is hit or miss with my TSC, even on chick starter. I have seen them run out.
Well I think I'll hold off on this grit for now. Save it for when they're all grown up, hehe. Better safe than sorry after all. We live a couple miles from a lake so I'll go find some fine ground sand there. Thanks for your help!
Grit to chickens is like teeth to other animals. Kids don't need teeth when eating baby food. Chick starter is baby food. As far as giving young chicks grit it won't hurt them but it isn't necessary. I also start giving them grit at a couple of days old because they do get a piece of bedding occasionally and i like to start them on treats at about a week or two of age. Good Luck
I put a tray filled with sand in with them. It provides grit and they love to bathe in it too. They fling it everywhere, but hey love it. That's what a very seasoned chicken farmer told me to do so I did. No problems yet.