I'm not Smitty but I use about the same size tote that you do PeggyO with a 40 watt GE Reveal bulb. Photographers use it in copy stands because it's sposed to show things in a natural light. No particular reason for that bulb, I just happened to have a pack of them that wasn't being used. My house temp drops to 60* at night and I only run the heater to 68-70* during the day so I know it's not real warm inside the tote.
10 different people will tell you 10 different ways to do something with each claiming their way is best and that everybody else's is stupid. That's the thing about chickens, they're easy to raise, it's not rocket science and almost anything will work, and usually does.
I claim my way is best, hahaha, because instead of heating the whole brooder I only heat the chicks and they have the option to self regulate their own temperature. They hang around under the light for a while then go to the cold end of the tote, eat drink & scratch around, then go back to the light, then go to the middle of the box & goof off, then go back to the light, then back to the feeder, etc etc all day long.
If you ever watch chickens in the real world, that's the same way they operate. Chicks don't stay under the hen where it's 100* all the time; they run around in the cold for an hour then get under the hen for about 15 minutes, then go find a sunny spot and roll in the dirt, then back to the hen, etc etc. They're in & out from under the hen all day as they self regulate their comfort zone. This is an acclimatization process that grows a healthy, hardy bird.
We're raising backyard chickens here, not sissy commercial production birds where 5,000 chicks will drop dead if the brooder isn't 95* with the temperature being lowered 1* each day or 10,000 hens stop laying if the lights go out for 2 hours.
