OK, so I have a 125 gallon tank. I have 50 pounds of CaribSea base reef rock, 90 pounds of Fiji, and 50 pounds of Marshall Island (no one told me I could just use 50% - 75% base rock and the rest LR
My tank might have too much rock, but I plan on removing most of it and stacking it differently. My fish dart in and out as I have it loosely stacked with many caves and openings.
So I'm still in the 1Ĺ - 2 pounds per gallon depending on the type of rock you have. Carribean rock is much denser so you need more to cover the same volume that Pacific rock with cover.
Aquascaping is the second part of the equation. If you stack the rocks densely you need more to fill the volume. Stack them loosely you need less.
The last part of the equation is how much rock do you need for biological filtration. It the rock is very porous (most Pacific LR
) then you use the 1 - 1Ĺ pounds/gallon. If the rock is dense you may need to go to the 1Ĺ - 2 pounds/gallon.