fungus??

[alexblanelayder]

i just picked up some perculas and the first day they were healthy and when i went to go and check up on them. One had fungus on his side. what could be the cause? funny thing is though is my other fish arn't catching it..... so im treating them with melafix is this Medicine good? :notsure:

 

[elfdoctors]

What do you mean by fungus? Fungal infections tend to be rare in marine aquaria because most forms of fungus can't grow in saltwater. This is part of the reason that salt is often used as a preservative - it prevents foods from rotting.
The most likely alternatives are:1)bacterial infections - fin and tail rots can often look like whitish bread moldy-looking growths on the fins or 2) brooklynella - this tends to look like a film across the body; it is particularly common in clownfish.
Are the fish otherwise eating and behaving okay? Are your readings okay?
Any chance of getting a pic?
Until we know what you have, it is difficult to recommend for or against any medications.