Need some help clarifying what this is

[Michael marturiello]

so about 3 months ago I put a bunch of my fish from my 200 gallon main display into quarantine tanks due to a nasty case of ich, I put copper in the tank and just let it do its thing one of the fish I put in these tanks was a purple tank that was super health he stayed health for the whole time he was in this tank until 2 nights ago I started realizing that he had a massive loss of his appetite and he was very lethargic and he was constantly breathing heavily and he seemed to have some weird white film in his gill I thought it was just stress so I took all the water out rinsed the whole qt setup and did a 50% water change and replaced the copper but by the next morning he was gone and he was very stiff to the touch, can anyone maybe help me figure out what happend and how to prevent/treat it in the future.

 

[threebuoys]

More info please.

What copper product, what concentration, what testing device was used?

Am I correct to understand the fish was in copper QT for three months? How often did you test?

What was the size of the QT? What other fish were in QT and in the tank with the tang?

How have the other fish made out?

 

[vetteguy53081]

so about 3 months ago I put a bunch of my fish from my 200 gallon main display into quarantine tanks due to a nasty case of ich, I put copper in the tank and just let it do its thing one of the fish I put in these tanks was a purple tank that was super health he stayed health for the whole time he was in this tank until 2 nights ago I started realizing that he had a massive loss of his appetite and he was very lethargic and he was constantly breathing heavily and he seemed to have some weird white film in his gill I thought it was just stress so I took all the water out rinsed the whole qt setup and did a 50% water change and replaced the copper but by the next morning he was gone and he was very stiff to the touch, can anyone maybe help me figure out what happend and how to prevent/treat it in the future.

Sorry to see. The purple looks slightly thin and you mentioned adding copper.
Were you using coppersafe or cupramine?
What level copper were you running and how were you testing it?
White film in gill can be protective film/mucus or reaction to copper if overdosed which will explain rapid breathing.
Other without more history can be low oxygen or in fact disease

Prevention is always a value and signs /first signs are heavy breathing and loss of appetite which are flags indication something is going on