Was it imported recently? Some hobbyists call it 'auranti wasting disease' because it's common in aurantimaculata,stewartii,bleheri and other sub tropicals.Not an expert but this is what I did when my 4" aurantimaculata got a cotton like growth on his face - constant water temp of 28c(only during treatment),dosed acriflavine and also salt.It got better within the course of a week.