i have a 90 gallon reef tank, the livestock are one yellow tang a sailfin tang three damsels one percula clown a maroon clown and a hawkfish. i have a light fixture setup with two pc lights in it one actinic and one 50/50. just the other day the 50/50 one burned out and now its just the actinic. i keep the lights on 12 hours a day but after the burnout the corals very rapidly seemed to decline, especially the blue xenia. and the kenya tree died. all my params are great, ammonia and nitrate and nitrite are 0 and ph is 8.2. could just a small reduction in light over a short period of time cause such havock on my coral, or do you believe it was soething else?