I’m not following your logic here… nobody said it was a whole tank crash.It’s isolated to one coral. It’s not a tank crash
Heres pics from a few hours before lights off
But certain corals can be more sensitive than others to certain things. We see this all the time in reefs where almost everything looks great except 1 or 2.
Taking away the variables makes it easier to decipher what’s actually going on is all I was saying.
Good luck. I gotta head out to work.