When to join different aged chicks

[KHAKI EGGS]

I have 8 hens, 1 rooster & a female guinea ( all 1 year old) Also, have 9 10 week old chicks. Wondering when I can put the younger ones in with the older ones.

 

[Fragosofarm]

How big of a run do you have them all in? I am having a similar issue

 

[13Bettys]

IF you are asking me, it is a fairly big run. The coop/run was built by the lady who lived here before me and she averaged 70 chickens. I modified the coop but they have plenty of room.
From what I've read on here and several other places they have to basically get used to each other and determine who's the boss and all of that good stuff. What I have decided would be best for me is to put the little ones in the run daily with the bigger chicks but bring them back in to their kennel at night. I am going to do this until I am confident that there won't be any issues during the night. Right now they all just kind of ignore each other but I do have one trouble maker in the younger group who is a white rock and not afraid of the bigger chicks at all. Even goes after them on occasion. She bites me too though, she's not a nice girl.