So I was doing my normal weekly water change today and I noticed one of my lemon tetras have a blackish color, breathing heavily but still eats and swims fine, also one of his eyes looks like its either blind or something is growing over it, water parameters are perfect except nitrate which I can't get lower, I've even done a full tank flush gradually over a day it's about 50 (old tank syndrome)
ammonia 0
nitrite 0
ph 7.5-7.6
Temp 77
I don't have a hospital tank for him/her i
Over filtrate the tank which is a 55 gallon, I have 1 aquaclear 110 and one aquaclear 70, and an air stone on full because I read it could be oxygen related I will try to take a pic of him but he's very skittish.
EDIT, he started floating on his side after I took the pic so I did euthanize him I do have 1 more out of a school of 7 that does not have black spots but his eye is staring to look like the one that I euthanized.
ammonia 0
nitrite 0
ph 7.5-7.6
Temp 77
I don't have a hospital tank for him/her i
Over filtrate the tank which is a 55 gallon, I have 1 aquaclear 110 and one aquaclear 70, and an air stone on full because I read it could be oxygen related I will try to take a pic of him but he's very skittish.
EDIT, he started floating on his side after I took the pic so I did euthanize him I do have 1 more out of a school of 7 that does not have black spots but his eye is staring to look like the one that I euthanized.