So if you wanted to save a coral, you need to qt it? Are you safe then. Or is it best to just pitch em?
You could QT it and keep dipping it through the life-cycle of the flatworm. I found out I had flat worms when I tore my 90 gallon down. I dipped my corals, and then cut off anything that was not alive, cut apart all branches. Then I re-dipped all of the frags the next 2 weeks. I watched all of the corals for 2 months before I even thought about transferring to my new tank....
The coral that had the worst infestation was the size of a baseball, I only recovered 4 small frags from it........Only one made it, and is growing well now....a nice mini-colony. I lost 70% of my acros through this process........but I had to be sure.