Clown fish started getting sick

lv_reefer · Oct 31, 2025

Hello all,
I have this clown fish for a month in QT. It underwent maracyn 2 treatment for 5 days due to other fish sickness. It was very good and active.
After the maracyn 2 treatment I did a 50% water change and left the QT rest for a few days before copper treatment.
During all time, ammonia level was maintained at zero, temp at 79F, salinity 1.020
I used copper power and gradually raised to 2.6 ppm over 3 days. Then I did some water change to lower Cu level to 2.5 and now 2.4ppm.
Today is the 4th day in Copper treatment and I suddenly found out this clown fish is abnormal and labor in breathing. It head seems to have a red spot and swimming against current
and stays at bottom.
What should I do?
Thank you

vetteguy53081 · Oct 31, 2025

lv_reefer said:
Hello all,
I have this clown fish for a month in QT. It underwent maracyn 2 treatment for 5 days due to other fish sickness. It was very good and active.
After the maracyn 2 treatment I did a 50% water change and left the QT rest for a few days before copper treatment.
During all time, ammonia level was maintained at zero, temp at 79F, salinity 1.020
I used copper power and gradually raised to 2.6 ppm over 3 days. Then I did some water change to lower Cu level to 2.5 and now 2.4ppm.
Today is the 4th day in Copper treatment and I suddenly found out this clown fish is abnormal and labor in breathing. It head seems to have a red spot and swimming against current
and stays at bottom.
What should I do?
Thank you

Not sure why you used maracyn 2 which is freshwater use and does little to nothing in Marine setting.
Salinity is low and best at 1.024 and I assume coppersafe? If so, ramping wastes valuable time and you want to get to maximum of 2.5ppm, recommended 2.25ppm to allow room for error.
How are you testing copper level?
Is fish attempting to eat at all?
Tail seems bitten, a sign of aggression and fish slightly thin