I just got this today and I was really wondering how much water to put into it? Should all the Stages be filled with water halfway, or a little bit? Also should the stem be filled up to the second tube or at the bottom? Sorry that pictures are crappy, best camera I have atm. http://s9.postimg.org/5isjsc5kf/Picture_68.jpg http://postimg.org/image/d01r7jv3f/