Seeing the bucket of Achilles reminded me of a joke I heard once.

"How do you pronounce Achilles? ... I kill these." Said by a large importer of tropical fish in LA.

Speaking of low oxygen levels at night in aquariums. It might be an idea to not dose carbon sources late evening and at night because the bacteria consume a lot of oxygen. They also lower the redox.

You're killing me Tim :) lol

Ya, I think it's well known not to dose carbon at night for that reason. Gonna add don't treat CP in QT with lots of zoas in the tank :)

Nobody really believes the O2 theory other than Sam and I, but I'm confident I can keep one of these in my tank.

That's the problem with being on the bleeding side of a cutting edge hobby. It's knowledge by experience.

Don't feel bad... I once learned the hard way not to acclimate boxfish with other fish. Also Frogfish can eat fish larger than themselves and Frogfish will eat Lionfish the same size. No respect amongst lawyers oops I mean predators. ;)

Ya, lessons are hard in this territory. But if my hypothesis is correct, I'll have better luck, or worse case, learn something else. If keep killing things tho, I might need to hire a lawyer. Know any?

Experience is a hard teacher. First comes the test, then the lesson... A flying saying that could apply to reefing, too.

I'm telling you, reducing temp a little (to 77-78) might be worth a shot too...

I bolus dose my kalk-vinegar just before lights on... should I be waiting til middle of the day? I actually thought that when I get the dosing pump set up, I would split it into three doses over the course of the night to give pH a little boost... now I'm second guessing that

No, temp is fine. It's 78-79, which gives me better growth on the coral. O2 levels that Sam and I are talking about are not in that 3% range you mentioned.
Dosing just before lights on is probably not an issue, and with most fish in a tank not heavily stocked, likely not really an issue after lights out. Could be, but not likely, depending on load.