I agree with the pipe bomb analogy. It would likely have taken my hand off if I had been holding the heater. Look what it did to someone elses tank!
That picture is from this thread -
http://www.plantedtank.net/forums/eq...ro-heater.html
The first page shows a tank blown out by an exploding Stealth Pro Heater. There are several more exploding heaters throughout the thread.
Another thread can be found here:
http://forum.simplydiscus.com/showth...th-Pro-Heater&
There are so many examples of this happening. I really think it is
all of these heaters. They haven't all exploded yet, but one day they may.