[DonRotolo]

OK, so you're using a piston to push air from the big PVC pipe into the smaller PVC pipe. I agree there is little safety to be concerned about with this scheme, but think about what is pushing the potato.

One clippard tank isn't enough, you don't have enough volume to move the piston fast enough. Try using as many as you can get, but plumbed in parallel, not in series, such that the greatest volume of air can move. Here pressure is secondary to volume.

If this isn't clear, I can explain further.

Don