And, to answer your other question, the tank has a cap that can be removed, so you can fill it that way. Do it this way the first time you use the tank.
After you insert the tank into the atty the first time, there is a little hole made in the cap to let the juice into the atty. When you want to refill many like to use a blunt tip needle syringe and fill through that hole.
Why? Most, it is just easier and tidy. Plus, some say that taking the cap off might loosen the cap eventually. After caps flying across the room to never never land, I got a syringe! Once and awhile they need to be washed out--so I take the caps off then.