"Do you use the fine, medium or coarse grit?" Bill, I use medium (grower grade) grit on pots up to 3 1/2" and the larger (developer grade) grit on bigger pots. Best, J. John T Lonsdale PhD 407 Edgewood Drive, Exton, Pennsylvania 19341, USA Home: 610 594 9232 Cell: 484 678 9856 Fax: 801 327 1266 Visit "Edgewood" - The Lonsdale Garden at http://www.edgewoodgardens.net/ USDA Zone 6b