At this age the shell is going to be a little soft. All turtle hatchlings' shells are soft as babies. I like to use nolvasan to treat shell rot in water turtles. Last summer i had a little res (rescued) that had a couple of white spots (shell rot), so i soaked & scrubbed the spots every other day for 2 weeks, in a diluted nolvasan solution. A soft toothbrush works well for this. It was gone completely after 2 weeks. good luck.