So I'm reading old threads on the Grit Mix.

In a potted environment, I've going with a fiberglass pot as I -think- to some degree - a terra or -crete- pot may be too much heat soak in the pot.

To that same analogy, been reading up up on soil mix for woody trees and would the same analogy I made regarding choice of pot material also be slightly the same on the sharp media component added to the potting mix ?