Integrating new chicks

[taylacline]

We have 2 older hens and got 6 new chicks recently. Currently they are in our bathtub "brooder".
We don't have a segregated area in our coop yet, but plan on it later on. I've seen where people will use a pop up play pen as an outside brooder. I have this one, it will fit in the coop no problem. When would be an okay time to set them up outside? Like if we set up the pop up pen in the coop now, would they be okay? I'm slightly worried about the bigger hens just because they are so much bigger but the chicks are going to out grow the bathtub quick. Attached is the pen I have

 

[rosemarythyme]

How old are the chicks? What are the temperatures like during the hours you'd have them out there? Main concern is making sure they have heat if needed, but if it's hot enough that won't be necessary.

 

[taylacline]

How old are the chicks? What are the temperatures like during the hours you'd have them out there? Main concern is making sure they have heat if needed, but if it's hot enough that won't be necessary.

It's in the low 60s at night and high 70s during the day but I have a brooder plate for them. And a heat lamp if need be.

They seem to be between 2 -3 weeks old. When purchased some were already older.

I'm worried about the pop up pen being enough of a barrier

 

[rosemarythyme]

It's in the low 60s at night and high 70s during the day but I have a brooder plate for them. And a heat lamp if need be.

They seem to be between 2 -3 weeks old. When purchased some were already older.

I'm worried about the pop up pen being enough of a barrier

Heat lamp might be risky with a tent/fabric type set up vs something metal which wouldn't burn on contact. The plate should be fine and given their ages it would be best to continue giving them the option of heat for another week or so, assuming power can be run out there.

I've never used one of these pens so I can't say for sure that it's a sturdy enough barrier, but I think it should be fine if it's strictly about separating chicks and hens, as chickens aren't too likely to press hard against it just to observe chicks (vs something like a dog that would just knock it over). I'm sure some folks on here have used one for integration so hopefully someone can confirm if it works or not?