Tough call. Some people have had luck with iodine and reef dips, others not. The important thing is to dip atleast 3 times 5 days apart. After the first dip, check for egg clusters along the base of the coral. Take a toothbrush and scrub them off in the dip water.
Otherwise, there is a pig dewormer called levimasole that works, but it is very harmful to the corals and you cant treat the main tank.
Hope this helps.