The first one looks like it could use a good brushing with at soft toothbrush to help get the old scoots off.. the second looks like it has pyramiding as Elliott said... just do the best you can for them it won't go away but it won't get worse either. Which is a good thing
I think you need a larger, more stable basking area. Looks like the turts are too heavy and they should completely dry off during basking, including their plastron (bottom shell).