I have it under Metal Halides about 4-6 hours a day, actinics from about 7:00am - 8:00pm, then moonlight LEDs.
It did decide to move last night...over next to my polyps

So I moved him this morning further away from them.
I'll just keep an eye on it. It looks very healthy, and within minutes after the MHs come on, he expands out and is really beautiful.