Bottled or tap water in Greece?
In Greece as in Serbia most of the people drink tap water but some also buy bottled water. Bottled water is cheaper in Greece so even if you decide to buy it during your holidays it will not be a big expense. If you still decide to use tap water it is always good to ask the owner of the accommodation if he drinks tha water from the tap too.
We can tell you from our experience that the water on Thassos is drinkable and that most of the locals do not buy bottled water.
The same situation is in the Olimpic region which is also considered to have water with a really good quality because it comes from the mountain Olympus. You can aslo use the water from the tap in the island Evia and in the region of Thessaloniki, from Stavros to Asprovalta.
Stavros is famous for the water with good quality.
In Sithonia the situation is a bit different. Water in the places like Toroni, Kalamitsi, Porto Koufo and Sykia has a specific smell and yellow colour so it is not advised to drink it although it has good quality. In some accommodations you can find water filters. However locals use this water for cooking.
In the bigger cities such as Thessaloniki, Athens, Volos, you can drink water from the tap. On Zakynthos and Corfu the water is not as good as in the other regions but is also depends from place because it changes from village to village.
As we said at the beginning, the best way to be sure is to ask the owner of your accommodation you are staying in if the water is drinkable or not because this changes from place to place.