When you say the scutes are lifting, you mean just the very top layer, right? (That`s OK.)
Cuttlebone is the stuff people buy for birds. Take off the hard backing, break a few pieces off and let them float in the tank. Your turtle can munch on it at will. Some turtles don`t take to it immediately, but if your turtle does, it`s a great way for him to get calcium and other trace minerals. Does your turtle eat veggies? Calcium-rich ones include chicory, collards (raw), dandelion, duckweed (an aquarium plant), endive, grape leaves, kale, and turnip greens. I also occasionally give my turtle the soft bones from salmon (packed in water and I rinse them well beforehand and break them up a little); bones from sardines packed in water will work also (rinse well beforehand). Hope this helps.