Many growers have included materials like pumice, coarse grit, coarse sand, granite chips, perlite, kitty litter, Turface etc. to improve drainage. Sometimes alone, but often in combination. Since the primary factor in improving drainage is particle size, what is the rationale for using more than one of these ingredients ? Most of the components are fairly inert; I have read that calcined clay (kitty litter, turface, drystall) has cation exchange properties, which apparently means it can store small amounts of nutrients (if present from added fertilizer), but other than that it seems to be personal preference ? Chad ________________________________ PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies).