Ok guys, in barbados we have hand made pottery from red clay.
Just like what this guy is displaying.
Now here is my question, could I take this type of clay and grind it down to make a substrate additive assuming that it would have a similar cation exchange rate.
If this is possible this could be epic cause i can get the broken pot for free. So i'll be doing 1/2 inch of dirt with osmocote 14-14-14, then this clay and then capping with normal aquarium gravel.
Views, warnings and advice are very welcomed here.