11 chicks need room. There also needs to be adequate room for large waterer and feeder. The chicks will quickly outgrow the equipment and the space, as shown. There is also little room to have a warm spot and a cooler spot for the chicks to regulate their body temperature. It is far too easy for the heat lamp to make the entire tub the same temperature; ie warm!!! My only advice is to get something much larger within just a couple of days. But... enjoy the chicks!!! And, yes. That 4x5 brooder will work for awhile, but they'll even outgrow that in an amazingly short period of time.