Somehow my tank was sitting at 84 degrees. My house is sitting at a toasty 63 degrees inside. I do have a 150w mh it is hanging about 6 inches from the water surface. I'm wondering if this heat is stressing my corals. I don't know if the rise is caused by the heater or what. "Hydro theo 150w" . I put the honeywell fan over the top like I used to during summer. I'm hoping this helps and I can tinker with the heater. Any advice would be grand.