[AdvanceAquatics]

Wow great Thought... i always went on visual effect and if anything live rock in the Sump/Ref to keep balanced. I wounder though If you place in the heavier rocks vers the lighter rocks, how dose that really effect the water due to displacement. If you had a 50g and you fallowed the rule of 3lbs( just example)per gal. Your at 150lbs of rock. Now even the Fiji mass is still at least 40% ( just example) which would mean any were between X amount of gal of water is lost due to mass displacement. Thus making a 50g really a (50-X=Y) Y amount tank. Meaning you actually over stocked your tank with rock vers the rule. No matter what it is. I agree its great to have an ideal of were to start, and I agree with over Bio filtration as much as one can before the eco gose out of control and back firers (LOL) but It really should fallow Gal.v Coral ( if reef > then Fish).v Fish (inch of Fish total).v Rock. simply because the filtraton will reflect the Reef>Fish or the Reef<Fish and so will the rock.

Very complex so in short:
if you had a 50g and you stocked < Fish=20"total you rock level would incorpate that such as (just example) 90-115lbs + a Higher Focus on Bio-Filtration.
Were it was <Reef=10"total your rock level would be greater 120-150lbs= filtration focuses on reef needs vers Fish needs.

I could be wronge in my thought but my rule would be more fish more water in tank stronger Bio filter, such as Sump/Ref. More Coral more rock and you could do with just Sump.

Im interested in others thoughts considering I never realy mentaly dug this deep of that topic LOL