I had a Butterflyfish die today. I had just done my bi weekly water change. for the last 2 changes i have treated ther tank for 48 hours prior with chem clean for Cyan control. He was one of my most active fish until after the last change he stopped being active i removed him to a quarantine tank for observation. He died this morning. Could the chem clean have hurt him. Although the other fish do not care for the bubbles it creates they all seem fine at this time.