do you have corals in your tank,
or any inverts,
Live rock?
that might lead to you to the type of medicine you will use,
OR if its that mild, you might be able to naturally nurse it back to health, i.e.
keep condition perfect, (no temp or salinity fluctuations,)
in addition to grear feeding, maybe garlic soaked or enriched food.
what size is your tank by the way