Skinny yellow tang

[Invigor]

I have a yellow tang since November 03 (2nd salty fish I've ever owned) and she will not fatten up. Her face became semi-translucent which I've read to be HLLE. I found out my mag running my sump was leaking electricity into the water. I did up a closed loop system so the pump is no longer sumbmersed in water -- since then I've noticed her face is back to normal but she is incredibly skinny.

I feed mysis in selcon, ocean nutrition marine 1 & 2, and nori about 4 times a day for the past 3 weeks and she doesn't seem to be getting any fatter. she's a pig and will eat everything I put in. She's got a 105g tank basically to herself, just a few chromis, gobies and a scooter, so there's no compition for food.

Has anyone had this happen to them or know how to plump her up?

TIA