I am at work all day so I really can not check the daily temperature till the weekend. However the lights are power compacts 65 watts with 4 bulbs. When I woke up this morning the tank was the same temperature as it was when the lights were on when I was going to bed last night. My house is 75 degrees. If it is the pump how do I fix it? I really do not want to buy a chiiler, as I feel like I spent a fortune in the last month to get this tank up and running; plus I am going on a cruise in 2 weeks. I am also checking the temperature with one of the stick on thermometers. How accurate are those in general? Thanks for your help.