I have used Dri-Stall for years. The only difference is that horticultural pumice is more expensive. Joe, Oceanside, CA On Apr 18, 2012, at 7:53 AM, David Moore wrote: > Hi, I ran into this thread and want to offer a clarification: as I > understand it, Dri-Stall is technically a 'calcined clay' (fired but not to > the point of full vitrification). This is why the material does not break > down like aggregated clay in its natural state. The physical > characteristics of the clay ensure that it retains its high CEC after firing > (which also burns out any organic matter.) > > > > I am looking for insight and observations (or even better, > scholarly/technical references) that might guide me on choosing proportions > of calcined clay and horticultural pumice when preparing a media for > long-term container growth of specimen plants. Here locally (Santa Cruz > County, CA) some of the bonsai enthusiasts are HUGE advocates for Dri-Stall, > I have them to thank for turning me onto this material. If these folks > trust their precious plants to Dri-Stall I consider this a solid > endorsement. > > > > I appreciate any insight and suggestions, thanks very much! > > > > Dave Moore > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/