What, if any, are the differences between viral and bacterial conjunctivitis (pink eye)? how does someone know which kind they have? does it always require a dr. visit or can it be treated at home?

Hard to guess: Watery eyes or clear mucus is more likely non-bacterial. Pink eye is usually a viral infection, sometimes allergies, sometimes a bacterial infection, and occasionally other causes. Symptoms usually go away in a few days, or up to a week or so. A doctor will want to recheck, if symptoms haven't gone away in a week, and recommend an eye doctor visit if symptoms are persistent or worse than average.