whats the worst that could happen?

[Samw]

I discovered early on that Flame Angels require higher oxygen levels than other fish. I've had 3 Flame Angels die since I started the hobby. The first one died within weeks because I didn't have enough aeration (I had no aeration equipment at the time. I was skimmerless. I only had powerheads for circulation.). I then added a skimmer and my 2nd Flame lasted many months until 1 day I turned off the skimmer and it died overnight while the Clowns and Tang were fine. My 3rd Flame, after many months, jumped and died. I leave my skimmer on 24/7 now and I no longer have mysterious Flame deaths. Out of all the fish that I've kept (which isn't many), I'd subjectively rank it as the number 2 most demanding fish for oxygen.