Howard I am using a 250 watt heat lamp now. I leave it on three days and off two. The water will get around 85 degrees if I leave it on all the time. The two days off will drop it around 75 degrees. I am getting the tank ready for my first tilapia, about 50 to 75. I have had the tank about a month and the electric bill went up about $ 8.00. I did not think that was bad, light, water pump, air pump.
