*sigh* Ram is sick, but I don't know what's wrong...

No clear external symptoms. He is definitely not his usual self, though. He's been hanging around the bottom (he usually swims around), has darkened and has overall lost his color. His eyes are no longer red. What is going on? What could it be?

Params are fine, and I just did a water change. I don't know what's going on.

Params:
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 5ppm

Been established for over a year.

Maintenance routine is 30% water change weekly.

I made a thread a few days back about how I thought my Ram was blind because he picks in the gravel AROUND the food, as if he can't see it...but when he does "find" a bit of food (either flake food or blood worms), he eats it vigorously. The past few days, though, he hasn't been eating very much.

I've been treating my tank with Jungle Parasite Food for the last few weeks because my Cardinals' poop was white and stringy. The Cardinals seem to be doing better, but now the Ram is lethargic. The Oto seems fine.

Yes, yes. I have been feeding the parasite food as directed on the bottle. The water temp. is constant @ 85 degrees F.

Perhaps I did too large of a water change. I did about 40%. I guess it's not good to do that much of a change? The problem is that in order to get all of the junk off the gravel on the bottom, I have to be vacuuming for a little bit, and by that time a significant amount of water has been siphoned out.

(Sorry for the slow responses...Architecture Grad. student here doing my best with an extremely busy schedule).

Thanks, everyone, for taking the time to answer my thread!