Thanks for the suggestion and I might talk to my pharmacist, though I have a great psychiatrist and neurologist with whom I "talk science" during our appts (I have some background in chemistry and medicine). Excessive drinking and urination are a 'normal' side effect of taking larger dosages lithium, which is indeed just above sodium on the periodic table and therefore has a similar composition to table salt. This side effect doesn't mean that the drug isn't the right med for me (getting up twice during the night is annoying but not dangerous and I'm not dehydrated or suffering from any other medical problem, tremors, etc. all the classic reasons people stop lithium).

I was hoping that other people in my situation might have tips from their own experiences for how they tweaked times of dosages, etc., that helped them out (i.e., things you don't see in medical journals). Already, I learned that taking 900 in the morning and 600 at night (i.e., the larger dosage in the morning) has made a positive difference for getting up in the middle of the night. But I'd love to hear other people's suggestions/advice. Thanks!