I cant figure out why the stupid heater in the fish tank is not working! It is a preset one that is suppose to keep the water at 78. The water has been at 74 the past few days at just now I look and it is at 76. I like to see it 80 cause they are happiest then. The heater at my house is on but for some reason it wont warm past 74 and I have it set to 77. I am worried they are going to freeze. Am I over reacting or should I get a new heater? The heater said it is for a 10-30 gallon tank not sure the wattage.