Hi everyone, I have acquired a very mistreated turtle who existed for 4 years with no lights or filter and being fed only pellets. With the help of this page and the guys at Amazing Amazon I've gotten him fish to eat, proper lights, calgrit, etc. but now I'm really concerned about his shell. Its looked like this for a few weeks. None of it is bumpy, pitted or soft. He has a concerning mark on his undershell but I'm not sure if it's rot or he just ran into something. I've just started putting him outside for 20 mins in the afternoon sun but he HATES to be handled or out of his tank. Should I be worried?