From brs. Year old tank. 40breeder 30-45 lbs of rock in there now. Five fish 2 occelaris clowns, ywg, mandrin, and coral beauty lt anemone and corals toadstool, finger leather, chalice, green slimer acro, candy cane, random zoas and mushrooms, red month cap, and a cup coral. Plus a cuc
just added 2 lbs of crushed from BRS about 4 days ago, wash it with RO/DI and you should be good. I checked mine for dead material and found some dead sponge like material on a small piece i used a new toothbrush to lift off the surface and soaked it in RO/DI. Everything seems fine so far.
i would added no problem as long as your aquarium is established, but try to add it like 5 pounds every week or so and make sure your skimmer is working cause its gonna create a small cycle.