I saw some ceramic heat emitters for sale at Petsmart today, the box said they emitted infrared... :? I though CHEs didn't emit anything. Not that I would have bought one there though, they were like twice the price as online. Would a 60 watt one be ok for a 20 gallon? Also, what happens if the temperature drops below 65? It dropped down to 66 last night, how worried should I be until I can get one? Last question, how much on average does it cost to build one crossfire viv?