Metronidazole should not be used long term, as it has proven to cause organ damage in fish. (see initial post) Also, Metro applied via feed should only be done based on the fishes weight. Dr. Edward J Noga suggests 25 mg/Kg of body weight/day for 5 to 10 days, or 100 mg/kg of body weight for 3 days. Retreat once if required.
I'm personally not convinced that this is a case of spironucleus (internal parasites), but possibly a bacterial infection, to which I would agree with Tom (Aquanero) - try a round of Kanamycin. (Kanaplex)
I'm personally not convinced that this is a case of spironucleus (internal parasites), but possibly a bacterial infection, to which I would agree with Tom (Aquanero) - try a round of Kanamycin. (Kanaplex)