When can i put my 3 weeks old chicks with my 7 week old chicks?

[CHICKENX2005]

I have a little less than 40 7 week old chicks of different breeds they are also living with 5 5 week old chicks and are getting along fine with them even though they weren't together until about a week ago. My question is when can I put my batch of about 50 3 week old chicks with them? The chicks from all the batches are of all different breeds si they are used to being around different sizes, colors, and shapes of chicks.
Thank you

 

[Mallards and Quail]

I recommend that you give them at least 1-2 more weeks before you put them with the older birds. If you decide to put them in sooner monitor the younger birds to make sure they aren’t getting picked on. Hope this helps.