Sooo two things.
My Duncan is alive and fairly open, but the tentacles on the polyps are not extending as nicely as before, and I am concerned I may yet lose the colony.
I am currently running LEDs and, as acans are one of my favorite corals and I am having the same issues described in the video (such as apparently healthy torch polyps detaching from their skeleton), I'm going to attempt to go half-T5s on this tank and see what happens. My T5 fixture is currently on my QT tank, so I will have to wait a while before attempting it. If that does not solve the problems, I will save up for a 4-bulb T5 fixture. I'm also planning to buy the new E5 bulbs for it as soon as I am financially able (after the berghias...which could be a while...bleh).