Question about mixing old and new

[lockedhearts]

I have 6 hens and a roo all about a year old. Am getting 15 mixed chicks (pullets and cockerels) 5 Silver Lakenvelder, 5 Golden Phoenix and 5 Mouttled Houdan. When the chicks are old enough to go outside will they be ok in the coop/run with the older ones, my roo is a cochin and small but bows his little self up on me all the time. I honestly plan on getting rid of him and keeping one of thenew ones (roo) or getting a calmer and gentler Roo.
I will also be selling some of these 15 as I only wanted a couple of each but had to order 5 for my feed store to get them in. I am paying $5.50 each for them but will sell them for less if anyone is interested.
I just don't know if I need to tell hubby we have to build another coop/run......

 

[chickflick]

No! The older chicks will hunt them down and peck at the little ones and make their lives miserable. You have to expost them to each other, but keep them separated. If you can make a pen within a pen, that would be great. I'd say for a few weeks. Then mix them, but keep a watchful eye on them. The little ones should be at least 4 months old, so they're big enoug to defend them selves.