I'll put it to you this way. I got over 50 lbs of dry, "Marco Rock" and put them in a brand new, sterile
sump with a brand new, sterile sand bed. I put no more than 3 decent sized pieces of mature
live rock on top and let it sit. Within a week, the Marco Rock was FILLED with gammarus amphipods, mysid shrimp, small munnid isopods etc. Within two weeks, there were also smallish bristle worms in the rock (I happen to love the worms that you all fear and remove from your systems). At that point, I'd have called the rock "Live".
It took a month or more for any algaes to show on the rock.
Dave
