That all pretty much rules out anything except a transient water quality issue, of which oxygen demand and/or high CO2 are the two common issues. I think turning off the skimmer and adding bacteria was just enough to push a percentage of the fish over.This will be my second-to-last post on this thread so we can move on.
My last post will be a week from today, for anyone who might still be interested in this and for any potential future viewers who may have stumbled on this thread. I’ll provide a wrap-up summary of what I’ve learned and any future tips I may have given to myself should I have known about risks associated with the most plausible drivers behind the die off.
It is now around 50 hours after the initial discovery of the die off, and the remaining fish are still behaving normally, which I define as no labored breathing, no erratic swimming patterns nor listless swimming patterns, no swimming against return pumps or power heads, demonstrating interest in appetite.
The inverts are also alive and, incidentally, two of my three shrimp have molted yesterday.
Jay