nitrox stick

I’m in the final stages of gathering the materials for a Nitrox Stick. I was going to go with a Static Blender chamber but the manufacturer is out of 2” components. So I’m using a 2” pvc pipe. What are your suggestions on either Practice Golf Balls or Bio-balls for the blending? …And why...

Hi I plan to buy a used Bauer jrii and make a Nitrox Stick to blend Nitrox 32. How safe is it for using a used compressor? Do I need to O2 any part on the compressor side before blending? Thanks