Sandblasting talk

So I'm getting pretty tired of driving over to Home Despot to buy bags of 30-mesh sand (they aren't that cheap, either), and would like to recycle some of the veritable sand dune I've got in my outdoor sandblasting area. I propose to make a filter similar to the one this fellow does on youtube:

DIY Sandblast Sand Drying and Screening - YouTube

He's using plastic window screen for a filter, but the abrasive media he's using is ground walnut shells, which I believe is finer than 30-mesh sand. Would anybody have a suggestion about what kind of screen I should use for 30-mesh?