Advice...please

I have a nandus that I have had for almost 2 years, that has been battling pop/cloudy eye for almost 3 weeks, I've been treating him in a Q tank, with Maracyn for 21/2 weeks, and it hasnt gotten any better....and today when i got home he is breathing very hard, and his fins are getting kinda "frayed" at the ends....what should I do...wait it out another week...or just put him out of his misery. I am at a loss on what to do. :sad

yea I keep the 10g cycled with a small female convict on her side of the divider. And when I have anything in the Q tank besides the con I do 2gal changes every day. So yea my nitrates are under 20ppm norlmally but when i up the changes im sure its even less.

Ans I dont think it started due to bad water quallity, because he is the only fish to get it, it only happened in one eye, and in my display tank where he usualy is the Nitrates are always below 30ppm. Ocasionally when I have to go out of town for an extra couple days it can go as high as 40ppm only for 3days max though.

I think I might just go ahead and put him down....but I dont want to "jump the gun" so to speak.