Anemone?

[BC564]

If you can...move him to the front of the tank and place in the same kind of conditions in the front of the tank....hopefully he will stay...it may take a few times....I had to move mine for a couple of weeks until I got the light and flow to his liking.....he doesnt move at all now....oh...I also fed him only in the front of the tank shortly after I placed him there....hoping he would think that it was a good food source in that location....I never fed him at the back of tank.