Thanks for the help. If he's got scarring then I will be fine with it. As long as he doesn't get worse and is in good health I am happy with that outcome. I will be doing water changes to get the Nitrates to less than 20ppm and keep it that way for a couple months.The open areas don’t look bad. Don’t have much of an eroded look to it. As the others have mentioned whether it’ll get better is hard to say. Seen small and shallow areas recover but some remanent left behind. Others spots not so much. Keep up the water changes and if not better then consider the hex shield. Best of luck.