I have my brooder set up early, and have been experimenting with the heating. It's a large cardboard box (a lawnmower came in it)...and I'm only going to have three chicks. I'm staying at my mother's so keeping a high wattage heat bulb on 24/7 was a negative. I decided to try a regular bulb and a reflector. I've experimented with a 60 watt, but had to keep the light a bit too close to the bottom of the brooder to reach the desired temp, and then it was only really warm right by the light. So I upped to a 75 watt bulb and placed the reflector outside the box on top of the hardware cloth (metal) covering. It seemed to be getting warm, but was still only at the desired temp right around under the bulb. I was looking at the cardboard and had a bright idea. Tin foil! So I placed a large piece of foil (shiny side facing into the brooder) on either side of one corner of the brooder, put the light with the 75 watt bulb nearer that corner, and have the thermometer lying on the bottom right now. Directly under the light it's already up to 100, so that means a little further away from the light it'll be just right! So anyone with a cardboard brooder might want to try this...it could help save on electricity costs.