White oak for what? Building an enclosure or for wood decor inside the tank?
Either way I guess it doesn't really matter, oak is a safe wood. However if it's a fresh branch from a tree, it's still best to bake it in the oven for a bit.
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!