For closing, I'm talking about "mentally closing the channels and storing your energy"... This is the part where you spend 1-2 minutes visualizing your energy in your dantien and it condenses into an energy pill. Doing this, will conserve the energy you've harvested, (so any stale energy runs out after your practice and not your fresh energy you've gained).
In fact, speaking of that, when you're done practicing, you may notice that your energy is still balancing (even after the closing) the idea of closing, is to keep the new energy and let your body naturally remove the old.
~Z
