i need a really good heater for a 9 gallon tank..i've never had issues before..normally i set it and it stays there..i've had two heaters and both i've set at max (86 or more) and the first was an aqueon and it never reached 75...got another one..its some mirrored fluval..its set to 86 the highest it can go..and its not even up to 80...both ran for 24 hours..