I've used 1½" and 1" diffusers to remove media from large tanks. I always have to deal with lack of flow from the client's pump for each particular diffuser to create enough vacumm to pup the media. In this case the media is Garnet (never seen a 22" tank filled with 30" of #60 Garnet and 10" of Anthracite on top). So even with a Goulds 3 HP I can't get enough juice to suck the Garnet out.

Will a shopvac suck wet Garnet out? Any ideas?