question about temp.

[chris s1]

if my tank temp is 78-80 and my room temp dropped down to say 50-60, is it possible the tank would crack?

 

[Mouse]

The degree of change is not what would make glass crack, its the speed of the change. Basically you would have to heat up a piece of glass to over 100 degC and then plunge it into icy water. Not that this would ever happen anyways. Mind you i have heard of a guy with a 400 gallon tank who cracked the front glass of his tank by heating it with a metal halide bulb on the stress bar, and then cracked it by pouring cold water on it once he realised how hot it had become. Doh!!