Anyway to dial in a thermostat on a stealth heater?

[dirtyblacksocks]

I've thrown out my stealth heaters packaging - but a 250 watt in my 60 gallon is only keeping the water at 80 degree's or so when I crank it to 89 degrees with plenty of circulation.

Is there anyway for me to dial in the thermostat so this thing will actually do what it's supposed to - can some one go over it for me? I'm fairly certain I had heard it's doable.

Thanks.

 

[CHOMPERS]

A lot of heaters no longer have temperature increments on them because they are not calibrated. They just have a + and - on both ends of the scale. It would cost too much to calibrate an aquarium heater and still have it economically competitive. Test it at two temperatures and see if the difference is the same. If it is, pop off the knob and replace it in the proper location (may not work depending on the brand). If the inaccuracy is different for the two temperatures, then just give up. That would indicate that the manufacturing tolerances on the thermostats were not adhered to when the temp increments were first determined.