Yellow Tang Recovery Time for Lateral Line?

MY yellow had a bad diet---lateral line set in--changed the diet...but top fin is still spiky and middle tissue not grown back in between---bottom fin also very short....from mid march to suddenly mid april, i noticed a huge difference



changed diet---seaweed, kelp flakes, marine algae---the detoriation stopped but its no late may and i dont know how long it will take to get him back to show form---



anyone ever deal with a yellow tang like this and how long it took to get him back to form? im patient...