I purchased a Xenia from swf.com. when i received it the piece looked great and did for the first week. Now for some reason all the - i guess you would call them polyps - look like they are getting whiter and smaller. I have a 75g with 2-250w MH both 10K. My actininc's died so i don't have those on right now. It is placed mid tank with pretty good water flow on it. What might be wrong?? Should it be lower in the tank not sure if the lights are too strong for it. My water parameters are great besides the temp getting well up into the high 80's due to the heat wave we had.