I'm really not sure...he's been acting very very funny the past 4 days, not eating (he loved to eat) and laying on the bottom. I finally couldn't take it any more and put him out of his misery (death by freezer). He was laboring to breath, etc. I did a test of all my water parameters and all checked out a ok and the other fish are fine. But just a very very sad lose. I've had him for such a long time.