>From: "Hans-Werner Hammen" <haweha@hotmail.com> "I do not talk about seramis, volume related water binding capacity = 25% >here, but about porous balls with an outer skin similar to these 8 mm balls >which are used for hydroculture. I roughly estimate their surfacial water! >Hans-Werner" Hi Hans-Werner: Not long ago, there was an interesting thread here at PBS on drainage dynamics, including a page in which there were the results of a number of experiments with very detailed information sent by one of our attendants. Among several other subjects the problem of water tables, container height, etc., were discussed. Very interesting. Regards Alberto _________________________________________________________________ Las mejores tiendas, los precios mas bajos, entregas en todo el mundo, YupiMSN Compras: http://latam.msn.com/compras/