I ordered the Pilson book from Amazon. I've read lots of theory, but no work with data showing how it work (or even if it works).
Randy mentions live rock and sand as denitrators -
http://www.advancedaquarist.com/2003/8/chemistry
he references it as nitrate generation on the surface of rock and sand can help it diffuse into the rock and sand for denitrification. That goes back to my discussion of the sand bed surface as a potential battle zone for dinos vs. algae where the dinos have the advantage.
but I don't see any supporting evidence showing depth of penetration of different elements inside rocks.
Equilibrium is fine, but that's a very slow process and through a very thin shell of rock.
It wouldn't be that hard - put a rock (one where a portion has been removed to test for nutrient content) in a controlled tank with very high nitrate and phosphate and measure the rate at which those elements are removed... and then remove the rock and cross-section to measure the nutrient content at different depths...
data...
It doesn't matter for the purpose of this thread - the question here is how to promote algae uptake of nutrients before dinos take it up. Looks like flow is one key variable in addition to the replenishing the missing nutrient (phosphate or nitrate).