I replaced my heater 500W aquatop heater for 120 gallon. Have it set for 80 but even replacement is staying at 84 degrees have 2 WaveMaker by redsea and 3 160s redsea lights. Could it be the lights they are 12 inches from top of the tank. The temp remains at 84 degrees even after lights are off for 10 hours. Any thoughts are appreciated