Read JAMA as there is evidence, and working with RN's who work with people more medically fragile than you is probably generally good advice. Caffeienated drinks don't count for fluid intake, is simple physiology, period, as caffiene will diuerese your volume. That is a fact. General fluid intake can be based on weight, ie if you weigh 120, you should drink 60oz, or your urine should be a color lighter than apple juice by noon. Medical diagnoses, and comorbidities, exercise intensity, can influence what you drink. You are probably a healthy adult, and what you described above, I suspect doesn't meet the minimum requirement.