Is that the high range or low range?
It is critical that you are able to maintain the system temperature below eighty-two degrees Fahrenheit. In the wild large colonies of Xenia breakup and fall apart when the water temperature rises at the end of summer. We have been told by several divers, who live in the South Pacific, that if the Xenia continued to grow at the rate they grow in the summer there would soon be nothing left on the reef but Xenia. Several times we been told that just when it seem like the Xenia would take over everything the colonies crashed and it was hard to find any adult Xenia. If you do not want your colonies of Xenia to crash in your reef system it is very important to maintain a lower temperature.
Information Source:
http://www.garf.org/xenia.htmlNot sure if you are in Huber Heights area but if you are your more then welcome to bring over some water and I can test for you to see if there is something a bit off.
Your light cycle seems a bit long as well. Not sure if that would effect anything.