a few questions about box turtles?

without knowing where they came from, its hard to tell. The shell chipping could be not enough humidity or not enough oils or minerals in the food.

if wild caught, like the eastern box turtles we have around here (Kentucky) chipped shells and scraped 'knees' come about from being hit by a car.

a home raised/ captive bred turt is probably digging or trying its best to escape.

I am guessing that maybe your enclosure is too small or they are bored?

Vita-Shell is a good product to try for the chipped shell. My daughter volunteers at a local reptile rescue center and a few years ago, we adopted one of the tortoises that had been abused. His shell was a mess and we used Vita-Shell with a real good outcome..you should be able to find it at your local pet store or online. As far as the red spots on their front legs, it kinda sounds like maybe there is something in their tank that they are rubbing against. Check for sharp rocks or an uncovered filter or water heater. Good luck!!!

wild-caught turtles do not make good pets. please release them in the same area that you found them.