rahul wrote:let me now categorise some commercial subs available now-a-days
A-inert like fluorite ,laterite ,soilrite etc which mostly depend on CEC,although they have no nutrition on its own.They dont affect water quality either.
Rahul I beg to differ to some extent regarding this Category "A". Are they really inert??
Laterite is rich in iron and if it comes in direct contact with the water column can cause havoc in the planted tank. Similarly Soilrite also should be topped well with inert substrates like sand gravels. Moreover the Irish Peat which is a constituent of Soilrite contains humic acids and is capable of altering the pH and kH of the water to a certain level. Even Seachem fluorite contains mainly micro elements and Potassium.
But you have rightly categorized these substrates in a different group which I guess can be renamed as not so rich in Ammonia/Nitrogen source for plants.