Help my loved fish is sick

[Petcrazy]

It seems okay?
Have you tested the water parameters?
Not just temperature and pH, but nitrates, nitrites, ammonia, salinity level etc.

Often when something goes wrong...the common questions that will be asked..and that you need to ask yourself...
How big is this tank?
How many fish are in it?
How often do you feed?
Have there been any new introductions into the tank?
What is your tank maintenance like?

Etc...