Here's the honest answer from someone who's spent 15 years in the travel industry: don't drink the tap water. Even I don't. But it's not a big deal. Every hotel gives you 2 free bottles a day. FamilyMart and 7-Eleven are everywhere — a 1.5L bottle costs about 3 yuan (40 cents). What I tell my clients: travel with a insulated thermos. Most hotels and restaurants have free hot water. Great for tea, and saves you buying plastic bottles all day. And yes, brushing your teeth with tap water is fine. Just don't swallow it.