Following because I have a similar question. I currently have six week old chicks out in a coop already and doing fine - no outside access yet because it's still under construction because of course I overplan and overbuild everything. I ordered more and they will be here third week of June, which will make them a full 12 weeks younger than my current flock. I plan on trying to introduce them at two months but think I'll have to wait until three months? I've been told to sneak them onto the roosts at night... Can I keep them in a brooder (stock water trough) for that long? I moved out my flock early because they were getting way, way too crowded - 110 gal trough. I can split the next group into two tanks if I have to but then I thought, will I have to then deal with two groups of younger chicks* squabbling while introducing them into the coop with older chicks?? Not to mention buying extras of everything and potentially having a room issue with so many troughs all over my horse barn (tack room is just not going to work, so the three-sided wash rack it will have to be.
*I can separate the younger chicks into "keeping" and "not keeping" groups to eliminate this potential issue, since I over-ordered after someone told me I had a crapton of cockrels in my current flock, and now I think I don't, so I have way too many to keep both groups and will have to sell some of them once they are a little older.