Drink bottled spring water and not tap water, tap water in Turkey is chlorinated and will give you the Turkey trotts (sh#ts) are not used to it, tastes awfull as well. A roadside cesme (fountain or spring) may say the word icilmez which means not to be drunk or icilebilir which means it can be drunk but i would avoid this unless you know for certain where the sorce of the spring originates from. Please check the bottles have not had the seal broken, if it has then leave well alone, chances are they have been filled with tap water.