...At this point my belief is something in the bacteria of vibrant had a drastically negative effect on my corals causing a lot of death and damage. ...
Sorry for your loss. I tend to agree with your thinking and I'm writing this post for others who read this thread.
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Just because lots of people have replied saying "Vibrant didn't kill my corals" does not mean that Vibrant won't kill your corals. The converse is also true.
However, I think BigRich's encounter is fairly controlled and shows that Vibrant did directly or indirectly, cause his coral death.
Corals are very sensitive creatures and have evolved over millions of years to live in a very particular environment.
Now, Vibrant is a bacteria culture. Bacteria can replicate INCREDIBLY fast. So anyone who says "He only dosed X ml in his tank, so that can't be the issue" doesn't understand bacteria.
A drop of a bacterial culture, placed in an ideal environment, can certainly replicate to incredible levels in 24hrs.
This doesn't mean the Vibrant bacteria is inherently good or bad for a reef tank. But it does mean that EVERY reef tank is different and Vibrant likely behaves differently in every tank.
I would proceed with caution and eyes wide open when choosing to dose an unknown bacteria in your tank.
Disclosure: My wife is a bio-chemist and my FIL is a PhD virologist who's spent decades studying bacteria and viruses. I've discussed this issue with them both extensively, before forming the opinion above.