I've got 120 GG eggs in the bator due to hatch off April 11th. I'm about to build a brooder (or maybe I need "plural" - "brooders) .... Even though I don't expect a 100% hatch, what size brooder (square feet floor space) would you suggest for .......say......80 chicks? (And I hope I get 80 chicks to put in there!)