I just got home and noticed one of my clowns having the issues above.  It's just 2 clowns in a tank I've had for about 2 years.  Nothing has been introduced to the tank anytime recently.  I noticed yesterday that the other clown was being unusually aggressive and chasing this clown around non-stop.  I haven't checked parameters yet but have pulled her our and am setting up a hospital tank.  She seems to be going downhill quickly. Any advice ASAP is appreciated.