Lets say we have two bottles that communicate via a tube. Level of water,will try to be the same at both bottles because If hydrosatic pressure is bigger at the one,will try after some seconds to become the same.(pushing down the water of bottle with the more watter). So lets say that level of water is the same at both bottles. Now,for example we take the first bottle and put that in bigger height(30 cm heigher than other bottle). We see that water from heigher bottle goes to bottle with less height. Hydrostatic pressure there is not because water were in the same level,but maybe now atomospheric pressure is active. Is correct that the heigher bottle has bigger atmospheric pressure,so it sends its water in the other bottle?? Sorry for my english. Thank you!!!