I'd say no, but it depends on the stability of your ambient temperature. Being near windows, heater/ac output ducting etc can alter local surroundings at times. Another great way to read the quality/efficiency of a heater is to watch how often and how long it comes on. A heater that is underpowered will stay on for hours and hours at a time, whereas a balanced ouptut will only come on 5-10 minutes or so. Much better to overpower than underpower, due to thermostat controlling. My 3/4 gallon reef used a 50 watt heater, came on for 1 minute at a time.
Welcome to our Forum Surgeon, can you post us some pics and descriptions about your tank>
Brandon M.
