I currently run one MJ900 and one MJ1200 on my 29 gallon. Once i installed the 1200...i have been having temp. problems??? I have my heater turned all they way down...and every few days i will have to unplug my heater due to water temps of about 83 or 94 degrees...which is obviously no good! My question is is it the new powerhead 1200 that causes this heat spike?? Or could it be my heater malfunctioning? I lost a fish once due to my water going up to 86 and i dont want this happening again. It is a huge pain having to constantly unplug and replug in my heater?! Any suggestions.....my house temp is always around 70 or so degrees. Any help would be appreciated! Thanks!