I was suggesting you add the dry dead base rock. LR
is a realative term and can mean a wide variety of things.
By the sounds of it, the rock you have now is most likely rock from the bottom of the tanks that have little or no "extra's" after the curing process. They still have an abundance of life such as worms, pods
, snails, stars and such but may lack a healthy coralline population or external coral hitchikers. The effects of this rock has absolutely no difference in filtration capacity than the uncured LR
you see some places offer.
If what you are looking for is the external "extra's" that comes with the uncured LR
then you may wish to look into to that but the addition of just dry base rock will be just the same in benefit to filtration. The rock you purchased from Liveaquaria will still seed it with the fauna, bacteria and other possible life just the same.