I bought 2 of these brooders and put them together last night. They are pretty tall in there. The box says you can raise 20 for 6 weeks. Obviously you can have more if they will only be in there short term. We had several 4 week olds we put in one of ours and I really don't think I would do more than 10 or 15 to 6 weeks old.That’s a good point. I know a lot of times chicks linger there for 3 or 4 weeks. They might get too tall. Especially the ducklings and cornish crosses. They might have to pull the old troughs out after all.
I was using a heat plate with the nipple waters on top, I put the plate moved up several inches with the waters on top and they fit with room to spare for my smallest chicks (newborn to 2 weeks) instead of the plate supplied.
For my older chicks I am using the heater supplied and they seem to be doing just fine. My husband LOVES that they can't jump out and poop all over the floor. He said why didn't you get those before. LOL (I would have LOVED to but they weren't an option "before")