Its a 300W Eheim. Tank is 140 gallons total and the heater is in the sump. I decided to log how often the heater comes on and it turns 2 times an hour. Temp on Apex is set to 79 to 80F. Is this too often? Should I get a bigger heater? My back up heater was giving off a charge so I got rid of it and haven't gotten another one yet.