One for layton, i got lost reading it, however main point was.
These results present a case for dynamic photoinhibition within the zooxanthellae of this captive coral, and suggest over-lighting is indeed a possibility in artificial conditions, even if a small-polyped stony coral is photoacclimated to high light intensity.
http://www.livingreefs.com/forums/saltwater-aquarium-articles/408-what-its-worth.html