CRUSHED CORAL RAISES YOUR NITRATES TOO HIGH, YOU SHOULD USE A DEEP SAND BED TO HELP MAINTIAN YOUR WATER QUALITY...TRUE CC HAS A BUFFERING EFFECT BUT IN THE LONG RUN YOU WILL HAVE NOTHING BUT TROUBLE WITH CC. IF YOU LOVE TO DO WATER CHANGES ALL THE TIME THEN CC IS FOR YOU. GET LIVE SAND, YOU AND YOUR FISH WILL BE HAPPIER