I'm using a Hydor Theo 25W heater in my filtered 5 gallon tank. I live in a dorm room where ambient room temperatures are constantly fluctuating, especially during the winter nights. I have the heater set at 83 degrees and it barely manages to get it up to 79 during the day and at night the temperature drops to 76. I don't really like all this fluctuation. I was wondering what I should do, either buy a different 25W heater or try the Hydor Theo 50W. Any suggestions?
-25W heater can't keep up with cold room temps
-Buy different 25W heater, or try same heater in 50W?
-Want consistent water temperature at 80 degrees.