We do have AC, I live in Michigan, and the room is kept 68-70 degrees. I have both a submersible and stick on thermometer, they usually say the same temp.
Everything I read tells me orandas/black moores, etc. like cold water. I see heaters galore in the pet stores....how do I keep the water cold? My 10 g. tank stays around 74-76 degrees without a heater.