Thanks Frank, Im keeping about 10 different species of ctenosaura. I asked on this forum because the monitor people seem to be a little more serious about lizard keeping and usually have larger collections than iguana people hence needing a dedicated room for their collection. My previous room used forced air from a furnace and that is the best if you can do it. I'm glad you said electric oil heater because I'm running one now on a thermostat. I guess I will have to run two. Thanks!