Every tourist asks this and answer is always same. Don't drink Hotel Zone tap water. Don't brush teeth with it. Buy 20-liter garrafones from OXXO for 35 pesos instead of paying 80 pesos for tiny hotel bottles.

Ice at restaurants usually fine because they use purified water. But why risk Montezuma's revenge in paradise? Look, you're spending thousands on vacation - don't ruin it over 35 peso water jugs. Here's the thing - intestinal disasters aren't worth the savings.