Count your blessings! I had to take a 5 gallon bucket half full of xenia to my store when I tried to clean my 40 gallon tank out of xenia.
2.5 gallons of xenia in my 40 gallon reef! I'm not sure who to blame for that either. It was either BrianE or SeanT that gave me a small colony of that stuff....
I think mine was the "white pom pom" xenia as well as the silvery pink regular(?) xenia. Just glad I never put star polyps or anthellia in my tank.