I let my chicks tell me when they don't need the heat light, I would move it up until they are comfy,(or lessen wattage on the light) I would be more apt to use at night longer then day, if they are in a temp controlled house they will need it a lot less then if they are in brooder outside. The first chicks I had I had done all the reading and knew it was 5 degrees less per week for weeks, my poor chicks I was sooooo by the book, but then I had a broody mom and chicks and saw they didn't freeze to death and die if they weren't heated for more then 2 minutes that opened my eyes on chicks for sure. I was so bad I wouldn't even take them out from the light and hold them aftaid they minute or two they weren't under the light would kill them! lolOkay! That makes me feel so relieved! Yes they have a very well protected run with other animals! I should probably wean them off of the lamp at night, right?