Sick Butterfly Fish

Question
QUESTION: I have a 150 gal tank with 15 fish, about 5 months old. Our favorite Butterfly fish has not eaten for 4 days. Normally the 1st one to eat. Did a 25% water change yesterday but no response. All chemicals check out OK. any suggestions? the other fish seem to be fine. Thanks

ANSWER: I would place him in a q-tank and watch him.  Is this fish being bullied? How is it's breathing shallow and rapid? Does it hover near the top of the tank.  Please let me know.

Thanks
Todd

---------- FOLLOW-UP ----------

QUESTION: Thanks Todd, He is not being bullied. He was one of the 1st fish in the tank (4 months ago). Breathing is irregular, spends some time near the top. Once in a while he still swims fast but for the most part not active.. sickly looking. I don't have a q tank. Any treatment available that might be able to treat him and not the entire tank? or maybe I need to get a q tank.. Thanks, Kent  

Answer
he has a parasite problem or an ick problem.  I would move him into a q-tank ASAP so he does not infect your other fish.  Your fish is displaying classics signs and symptoms.Does he have white speck on his body?  Copper treatment is the preferred course of action here but it must be done in the q-tank. Not your main tank!!  buy a small ten gallon tank.
and place him in there for two weeks.  The only problem ( I do not keep butterflies) they are a bit sensitive to copper.  Try Doctor Foster and smith online is check which medicine is is best for your specific fish. even though the other fish are fine eventually they will get infected.  Do you own a uv sterilizer?  They are great for prevent of certain diseases.  If you need anything please e-mail me back

Good luck
Todd