We are getting 6 chicks on Wed. We have a Rubbermaid 45 gal tub that we converted to a brooder. We cut out center top of lid and put in wire. This gives a lid to the coop. We purchased a heat lamp.. 250 watt / infarred lamp. Question: Do we need ventilation in the sides? Will the lamp get too hot for the Rubbermaid tub? Should lamp remain on top of lid or inside the tub?