Interesting. I had never considered that. Thanks for breaking it down. On Dec 7, 2009, at 12:24 PM, Paul M. Wallace wrote: > Dear Shango, > > There are several models for substrates in planted tanks used today. In > general, the most popular "planted" technique is to use a deep & rich > substrates with things like plant tabs and iron supplements. If you are > using an undergravel filter these materials are either pulled into the water > or so small they plug the UGF. I hear that UGF's grow excellent roots and > there is no argueing with Roy's success. > > -Paul > _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member