It seems like I've been posting a lot on this topic but in my other threads I was talking about like a "plague" that killed most of my fish but not my discus. A couple days ago my one blue diamond lost some of his color near his gills, was less active and hiding at times. He will eat like a pig thought. I'm in the Pittsburgh area to see family for the holidays so I really can't do anything but Is been driving me crazy. Is this something I should worry about or ask my petsitter to do something?