Depends on how bad the scars are. I have a purple tang that had hlle scars for about 3 years before I got it. I started soaking my nori in fish oil and Selcon vitamin supplement and the scars started healing. It has been about 6 months and the smaller scars on one side have healed over, and the bigger scar on the other side is almost healed. It grew new purple skin back that even matches the speckled/striped pattern of her skin. It is slightly darker than the rest of the skin and you can tell where the scars used to be. I think there is a point where they won’t heal back, if the damage is deeper than just skin. Make sure your water quality is good, I think that’s a big factor that causes HLLE. A picture would help.