Re: Modular substrate design

["Don Matakis" <dmatakis at charter_net>]

> > I thought I would invite discussion on Duplas modular substrate design
> > called Creativ. I have been keeping an eye on this product since it was
> > first announced on Duplas WEB site, and since it became available in the
> > USA.  I became intrigued by its potential.

Here is a great article on George Booths site on heating coils, laterite and
plant growth needs.
http://www.frii.com/~gbooth/AquaticConcepts/Articles/AFM_Laterite.htm  It
would explain why I never had a nitrate spike. But even more interesting is
this statement:
Only under the special conditions including substrates relatively high in
cation exchange capacity and oxygen content can the tremendous surface area
and nutrient adsorbing power of root hairs be optimized in an aquarium.
(Adsorption is the direct exchange of a nutrient cation such as NH4 from an
exchange site on a substrate for a H+ from H2(CO2) from a root hair) Plants
in other systems have no cation rich substrate for roots to exploit, so
don't mass root hairs. They are less efficient. Plants in these other
systems can do quite well taking nutrients up from the water by absorption.
(Absorption is the drawing in of nutrients as the plant draws in water.)
Higher plants have developed vascular systems which prefer to adsorb through
roots. Here is George's main address:
 http://www.frii.com/~gbooth/AquaticConcepts/ (Knowledge through research
and practical application always leads to more questions. Therein lies the
joy.) Don M.