You could attack the problem a different way and try to cut down on your nutrients...
Wet skim, add carbon, change more volume of water when it comes to water change time...
You'd be surprised... all my aiptasia went away by themselves when I added a second skimmer and 2 more bags of carbon...
My xenia quit growing too... it lives... looks good, but just doesnt grow like a weed any more and I am happy with that.