I jinxed myself with this post. The new 300w I just got from Dr. Foster Smith just died. So that sucks. I will try another one now I think, perhaps one really large one instead of numerous small ones.
The 300w is throwing stray voltage into the water even when dead, I could feel it. I can also feel a tiny bit in my tank so I think one of the other 3 stealths in it may be messed up too... It made a kind of sizzling noise when it would turn on these last couple days but I thought it was normal because it was a pretty big heater, guess not.
I'll be emailing Dr. Foster Smith for a return and hopefully a credit towards something else because they don't sell anything larger than 500w.