Depends on what you want to do.
If you want to polish, go with glass bead.
If you want to remove material like rust & paint, use the ground glass. Ive been using ground glass in both my sand blaster and my small cabinet. I like it , it works well.
I use both the fine and medium grits.
Get a bag of each and try them, that's what I did
The stuff I buy goes for about $13.00 a bag
It's put out by Opta Minerals. They have a web site
http://www.optaminerals.com/ I get it from my welding supplier.
