And as a side note-the cookie tin heaters worked awesome. We bought the 16 gauge 25' outdoor extension cord for $8 at WalMart and used it just like you do Romax. Ran it along the side of the house and spliced it and put plug-in receptacles in each of those pens. It's plugged into the receptacle on the back of the house. So when it's above freezing all I have to do is unplug it at the back of the house and it cuts power to all the water heaters in those pens. What a relief.