Just had 2 heaters go out after a storm took our power out. Dont have an extra $100 right now so im down to 68-70 in my cichlids tank, Glad to hear they can survive..
The tropics do not fluctuate as much as one may think. Of course there is rain fall ( even teh rain is not cold ) but changes are not so profound.
I never change temps. Water chamfes are more than enough to imitate a showering cold rain....