the best way to control it imo is to use a sizzors to cut stalks ( remove as fast as possible so they will not drift away. if not careful they will get lodged under a rock and will grow everywhere.) onced removed put in a small container of tank water , they will slime, after a few minutes rubber band to a rock (not to tight)and put back in tank as close as possible to the origional location. 2-4 days later remove rubber band and trade for other coral.