We had an Open Brain in our 75g under 440w of
VHO for 3 years, and the coral *flourished*. It grew from about 4" in diameter, to about 9" in diameter in the time.
Robert Fenner had once emailed me and said that ours was one of the largest he had seen in captivity.
When we set up the 180g, it was adopted by another home - it didn't like the flow of the 180g (too much).