Please answer the following questions & we can possibly help better.
How long has the tank been set up?
Tank mates; what kind & how many of each?
Brand of food(s), type, how much & how often fed?
Water change schedule?
How much water is changed?
When was the last water change & how much water was changed?
Brand of water conditioner?
Do you add anything other than water conditioner to the water; if so what?
Water test results for ammonia, nitrites, nitrates & Ph?
Treatments already given?
Describe current appearance & behavior of fish.