Heater Calibration

[oscar52]

I know this going to sound soft, but how do I go about calibrating my heater (Jewel 200W)

Problem I have, is my tank now displays an internal air temp (its empty) of between 75 and 77 F, therefore water would be roughly the same eventually. This makes it difficult to calibrate the heater to the required temp. I cant see my room temp dropping much below what it is, but if we happen to get a cold snap, the heater would be a good idea.

So to cut to the chase, how to I calibrate to 75F given that is the ambient temperature.

 

[fishwatcher]

what I would do is set it slightly higher than 75, and let the water warm up, keeping a close eye on it in case it starts climbing too high. Once it gets a little higher temp (around 78-79), turn it down just a tiny bit at a time, checking the temp every few hours, until it is the temp you want it to be.
HTH!