I recently moved to Arkansas and resetup my 240. I had a 6" pwdr blue and CB butterfly, Kole tang and others in it before the move and gave them to a good friend. I bought a small pwdr blue, CB butterfly, and yellow tang to start with now and have them in quarantine. They have been there for 6 weeks now and they are scratching their gills and they twitch, not all the time but quite a bit during the day. There is no external signs of anything, no ich, velvet,odinium. The CB had some tuffs on his tail fin for a few weeks after having him for a week and I treated the tank with Maracyn and Maracyn-two by Mardell and that is gone. I have had Mardells coppersafe in there for 6 weeks now at a concentration of 2 ppm and the scratching and twitching still goes on. Is there some gill disease that copper is not the cure for??? I am thinking of removing the coppersafe and using cupramine by seachem, as I have used that years ago and had good luck. Any suggestions. John