In a blender, combine water, milk, flour, sugar and vanilla, lemon juice and eggs.
Blend the mixture until very smooth and free of lumps.
Pour the batter into a large liquid measuring cup or a bowl, cover and refrigerate for at least 1 hour or overnight.
Using a pastry brush dipped in melted butter, lightly grease surface of a 9-inch crêpe pan or nonstick fry pan and place over medium heat. Use a 1/4-cup with batter to just below the lip. Holding the pan at an angle above the burner, pour the batter into the pan close to one edge. Quickly swirl the pan so the batter covers the entire bottom of the pan. This should happen very fast since the batter will start to cook upon contact with the hot pan.
Cook, shaking the pan from time to time, until the crepe begins to bubble, the bottom is lightly browned and the batter looks set, about 1 minute.
Use a small offset spatula to lift the edge of the crepe, carefully flip the crepe over in the pan. Cook until the second side is slightly browned and set.
Transfer the finished crepe to a plate. Repeat to cook the remaining batter, greasing the pan with more butter each time. Stack the cooked crepes on the plate between squares of wax paper.