I have 2 tanks, fixing to have a 3rd. I am trying to decide many things, one of which is a heater. Currently my thermostat is broke, so I am using a timer and watching it closely. So far I am good, but I don't want to take a chance. What are the good and bad everybody has experienced with heaters? I am not too worried about how much I spend because I want it to last. I need some honest opinions.