Don't drink the tap water! And use only bottled water to brush your teeth!
Take a couple of bottles of water from home with you. There are water coolers with filtered water in them in every building. You can also ask the bartenders to fill your bottle for you. All water used in the bars and restaurants is filtered and is safe to drink.
Also remember that if you leave the resort, be cautious when it comes to salads or drinks with ice. You never know if it's filtered water or not.
Hope you have a fabulous time!
Debs