Casa Mexicana in town has a purification system, so their tap water is drinkable (and there are signs in the room to let you know.) The other places we have stayed - Caribe Blu, Villablanca & Villa Las Anclas - have all provided bottled water for drinking, brushing your teeth, etc.
cruiser - so do they have an in-house purification system at FA? Or were you just winging it with no detrimental results?
DiverKat--
I was winging it with no detrimental results. It was late at night, I was very thirsty and tired and didn't want to go downstairs to get a bottled water so had a big glass out of the tap.