Thanks, I have had my 75 gal for 8 months and then did a switch over to my 125 gal 4 weeks ago. I have a large yellow tang and a foxface that I have had for over 6 months and they are fine. I just got the powder blue about 5-6 weeks ago and he was doing fine until yesterday. The clowns and damsels and cardinals that I had since I set up my 75 gal tank are all doing ok. In fact the cardinal has tripled in size since I got him and my coral banded shrimp has molted since I have put him in the 125. The powder blue is the first fish I have lost to illness since I have started in saltwater fish. I do my water tests every 3-4 days (the ammonia I do everyother day since I am with a new tank although I used everything out of the 75 to speed up cycling) and do a 30% water change as soon as the reading go up. I didn't have time to QT the powder blue. He was fine in the morning and by the time I got home from work he had the white all over him and he was dead in just a few hours. What I am worried about is that whatever he had he passed on to my other fish before I could get him out. The only other losses I suffered in the tank were due to a chocolate chip star that I caught eating a flame scallop and a curly Q.