This morning when I woke up, my Tang (Dory) has developed little white spots all over her body. Is this ich? I have never had any diseases in any of my tanks in four+ years. Everyone else in the tank looks fine. Dory is still active and feeding, but looks awful. Catching her to put in a QT is almost impossible without taking the whole tank apart. Does anyone know if I can safely medicate the whole tank? If so, with what. I have had Dory for four years and don't want to lose her!