"Boomer" wrote in message ...
Lets answer a question with a question. You are aware that LR also
brings about facultative dentrification and converts NO3 --- N2 (g).

Are there any worms or snails in the very fine pores of the LR......Nope

Interesting comparison... I do not know how LR works in this task.
But, in contrary, I see some worms drilling holes in my LR...

Think convection and diffusion

What stops convection/diffusion of oxygen into anoxic layers?