I also use a standard sized socket (ceramic) with a 40w light bulb in it and plastic 1 gallon waterers. It all works well unless it gets down to below zero, then it is not enough, but thats not a daily thing.
I have them in all my pens and love them. I also have them all plugged into Therocubes so that they turn on at 35°F....so they do not run all day long.
I have them in all my pens and love them. I also have them all plugged into Therocubes so that they turn on at 35°F....so they do not run all day long.