Regal Tang Tail Not Healing

[tdileo]

About two months ago I spent about 5 hours of my day breaking down a tank that was terribly neglected since the owner finally felt bad. With nitrates so high none of the test kits I tried could give me an accurate reading, I knew that there would be internal damage that I couldn’t see. These fish were only fed goldfish flakes for years, so they were also malnourished. Anyway, to my main point: one of the fish that I ended up keeping instead of giving to my LFS was a regal tang. It’s dorsal fins and tail fin were shredded pretty badly and while the dorsal is looking normal now, it’s tail is pretty tattered. Is there any reason it’s not healing? Not an easy fish to photograph, but here is the best I could get.

I’ve been feeding an array of high quality pellets, mysis, and other frozen foods as well as ensuring she always has nori to graze on.

 

[Salty1962]

I would add something like Selcon in it's food to boost it's immune system.

 

[4FordFamily]

Was it getting beat up by a tankmate?

Sometimes flukes can tatter fins as well. How long have you had it, was this a sudden change or a slow gradual increase of tail damage?

I agree with @Salty1962 with regards to selcon either way