Indefinite if kept dry; store in a Flinn ChemSaf™ Bag.
Not meant to be put in solution.
Non-indicating (D0011): White. Indicating (D0054 or D0012): Blue, changes to pink when saturated
Your best choice when using a desiccator. Drierite® is anhydrous calcium sulfate, granule size is 8 mesh. Available in two forms: indicating and non-indicating. Indicating means the desiccant will change color when fully saturated.