40 gallon tank
parameters: 0 ammonia, 0 nitrite, 5 nitrate, ph 7.6
Hi, one out of two of my goldfish has been bottom sitting for well over a month with periodical rapid breathing, pivoting upward before resettling back onto the substrate. I've been unable to find any external signs of illness and it will still eat provided I place food in front of it. Thinking it was flukes, I tried Prazipro which was ineffective, then onto a Kanaplex food treatment thinking it was a bacterial infection (I did not use Focus because I wasn't aware you needed it for binding) which also gave no signs of relief. This behavior has been consistent throughout the duration of the illness and has remained the same with no signs of worsening or bettering. I'm extremely lost as to what this is and I would appreciate any help in diagnosing it. Thanks