Heaters seem to be one of the few areas where technology hasn't kept up with other areas.  I  know there are several "new" types.  I have actually tried one of the most recommended ones...on second thought, I am not going to mention the name.  Let's just say it is a titanium heater rod and temperature sensor, with a supposed infallible electronic controller.  This was an utter failure.  No less than twice in three weeks this thing sent the temperature to near or over 90 degrees.  This while having no obvious, nor apparent cause other than possibly it was too close to the tank itself.  The second time I tried one of these the controller was several feet from the tank and so had no reason to be affected by it.  Yet the same thing happened.  If this was the cause, these Mfg.'s need to go back to the drawing board.  The way I see it if I have to operate one of these in complete isolation from the tank I don't want it.  Many have never had any issues with them so maybe I just got a couple of bad ones, I don't know.  What I do know is that I'm not likely to try them again any time soon.

    Now ordinarily I would rant and rave at the Mfg. until they replaced the unit.  However in this case I just ate my loss and went back to my old standby, Visi-Therm.  If there is one heater brand that has never, I repeat Never, let me down this is it! I have one that is going on 9 years old.  I have abused these things almost to the point of breaking, yet like the Timex commercial, they just keep ticking.  Their only issue is that the calibration scale is usually incorrect, but once you get it dialed in it stays put.

    The only other heater I can recommend is the hang over the side Penn Plax heaters.  These things can also take some torture, although I would never use one on a larger tank, they are great for quarantine and Nano tanks.

    One thing I would like to mention about heaters is that on a larger tank, use multiples, not singles.  For example, say you have a need for 300 watts of heat.  Do NOT use one 300 watt heater.  Spend the several extra dollars and get 2 150 watt heaters instead, you can thank me latter.  Dial one in just below the other, try to get it to kick on at about a degree lower, or less if you can tweak it.  Also, buy one extra, you just never know when one might go belly up, and in the  meantime you may use it for heating top off and change water.