I have a small clown, cardinal, emerald crab, snails and hermits. Also have a hammer, an acan frag, some zoas, and a kenya tree. I could probably add a little at a time, but have some new frags to pick up from Wicked Demon. Guess most of those could sit on the bottom until I get all the rock added and my LED's installed. Guess a little at a time makes the most sense.