My husband came home from work yesterday happy about a large wooden crate that came into work with parts in it. We are picking it up later to make a brooder out of it. He says it is about 3x3. We ordered 12 chicks from Ideal and it sound like there will be extras added for warmth. So we are looking at possible 25 chicks max. I really don't want to keep making a bigger brooder each week or two so what size should this thing be to get them through at least 4 weeks. They aren't coming till mid April and we are in Mi. so the weather gets nice in mid May so I am hoping to have them in the coop with a light at night for warmth at the end of week 4.