Very cool, thanks for the explanation victork.
Here is what I did to adjust the working pressure on my regulator.
First, I used a 7/16" wrench to remove the domed nut in the center of the regulator. If you look beneath this you will notice a little recess where an allen key can be placed.
Then, making sure the needle valve was slightly open, I opened the main tank, and using a 4 mm allen key, loosened that portion until my working pressure was down to 20 psi
After you have the working pressure to where you want it to be. simply place and tighten the domed nut that was originally removed.
Now that I know how to change the working pressure, I am wondering what I should have it set at? My tank is a 10gal running a nano ceramic diffuser. I was leaning towards using something like 10 psi, is that a reasonable amount, or should it be different?