I have about 90+lbs of live rock in my tank and it's definatly the way to go. I love the corals and other obvious critters in my tank, but I also love to get face to face with the glass and observe all of the tiny life that flourishes in there as well. I hand picked 4 or 5 of my rocks because of the star polyps, mushrooms, and zoas that they had. But a couple of them came with extras I didn't know about, mostly red sponges. Though as my tank cycled, other critters from deep in the rocks began to spread. I have several small colonies of feather dusters, brissle worms, and other small shrimp-like animals that I honestly don't know much about. The live rock definatly adds some personality to the tank.