I have a Veiltail in a 5.5g filtered, heated (80), still unicycled tank. He is dark in color (red & blue), fins have always had a dark border (not sure if that's natural or not). His fins started looking ragged, & he got a pin hole in the anal fin which ended up tearing to the edge. It never healed. I treated with 5 days of MarcynII. No improvement. Waited a week & treated with 1tsp/g aquarium salt w/ 50% water changes every other day re-adding 50% salt w/ each change. No improvement. Fins con't yo worsen. It looks like pieces fall off. I have never seen him tail bite. He is energetic & eats well (Omega pellets 3/day, fasting once/wk.). I have attached a picture. Is this fin rot? Any ideas how to treat? I keep water very clean & test often since tank is unicycled. Please help!