I do private caregiving for a retired military man with stenosis of the spine and a stretched bladder. His urine is dark when he isn't drinking a lot of fluids but he feels like we are to pushy when we keep telling him to drink. I would like to know how much water he needs a day to stay hydrated? He also has a glass of soda and a cocktail every day. I'm afraid of him dehydrating or him having kidney problems.