Did your friend "kidnap" the turtle? How long has he/she had it? Its spring and will start growing rapidly with the proper nutrition. It does need a full spectrum bulb. The limestone worries me as it might affect the pH. (Farmers add limestone to a field for that purpose.) If you do release it (and it was kidnapped), I recommend doing it as close as possible to the original. Hopefully that niche that the turtle occupied has not been filled by another. Releasing to a site that has lots of softies is ok, but it troubles me because its probably "full."