I picked up a 10 watt Aqueon mini heater for my fiances 2 gallon betta tank. Its a preset heater and supposed to be calibrated for mid 70's but this one has the tank sitting at 85.6! The tank is still cycling so no fish yet. Is there a better option for this size tank??? And please let me settle this before I catch a ton of flack. I know a 2 gallon isn't the ideal betta tank. I wanted to get her a 5 gal, but this is what my fiance wanted cuz it fits on her desk, so its what she got. Happy wife, happy life right? Thanks!