 To answer the age-old question of can a person drink too much water, the doctor says they can. She says the CDC advises a person shouldn't drink more than 48 ounces of water or other fluids in one hour because the liquid can dilute the concentration of salts in our blood. When faced with the choice of water, an electrolyte drink, an iced coffee, or alcohol, Wen explains that water is the best choice of all.