I think within the range is okay, temperature in nature fluctuates. That heater looks pretty good. I have aqueon pro and eheim jager, both 200W may be for 75 gallon I will get this.I have a new heater on the way. This one is starting to crap out. Fluctuates 3-4 degrees F too often. It stays well within range of what flowerhorns can handle but I don't like that much fluctuation. I went with the Fluval E300. Heard good things and i got it for only 30 bucks. This one has a guard so that will help too haha.