Sick Perc. Clown

[bergshawn]

Have a mated pair of True Percs.. Have had them for at least 6 months now without any problems. Yesterday the male (smaller of the two) was discolored and did not look right, looking pale. He was still swimming around, but seemed timid, which isn't like him at all.
I fed and all the fish ate, including him. Today I get home from work and he is stuck up against my overflow, but still alive. I immediately shut off the pump in my sump and the overflow stops taking in more water, and he swims to the bottom of tank. He is moving, but is remaining at the bottom of the tank, only swimming a little bit at a time, and breathing a little more rapidly than normal. He does not show any signs of ICH, nor do any other fish in the tank. I did do a water change this past Sunday, but this just started yesterday. I tested my water params last night when I first noticed the problem, and here they are:
Ammonia: 0
Nitrite: 0
Nitrate: 10
Alk: 3.3689
KH: 9.44
PH: 8.0
I know the Alk and KH is a little on the high side. Could this be the problem? All the other fish in the tank seem fine.
Any help would be appreciated. I'd really like the little guy to get better, even though I know the outlook isn't good at all.

 

[beth]

I have seen this happen with clowns here with hobbyists on the BB as well as my own. Mysterious illness. It could be that the fish developed a bacterial infection. By chance have you noticed any harrassment of this fish with fellow tankmates? What other fish do you have in the tank? Any new additions recently?
The thing to do is move the sick fish to a QT and try to treat with antibiotics. However, a fish that gets sucked in by filters is usually well on his way to death.
What do you feed your fish and what type of tank do you have?