heliofungia (plate coral)

[Tanman]

me again, the plate coral i have stopped opening up for me, i can see his little tenticals but their all 1/8th of what they use to be, everything else in my tank is doing awsome, but the plate. even my xenia's are all the way out there just not pulsing (too much water flow i think). i know that the plate likes the bottom, could my bulbs need changing? or is there something else i'm over looking?