How did he manage to do that, hope he's ok, sometimes then can be abit of swine to stick on again, but it will.
I dont know how you will do this, but whatever way you decide to act upon it, be careful. If your thermometer has mercury in it. If the mercury gets out, the catfish will most likely be poisoned and the other fish in the tank will probably be affected too!
I've only ever had one thermometer smash, but luckily it was out of the tank and was in the sink, so most of the balls were not too dangerous.
Hope he's ok
I know RTC's can get big, but how big exactly? I think it was either 3 or 6 foot...