I've been working at a pet store for about 2 years. I've learned a lto about saltwater but this stumps me. My cousin, I found out recently, started his own reef tank business so to speak. He builds and sells tanks and PC lighting, metal halide, you name it. He also has a ton of fish/inverts. He decided to bring me a emerald brittle star for my 2 month old 20 gal saltwater tank, consisting of rock, two turbos, and two blue leg hermits, and a banggai cardinal (I had two, but one killed the other). So far everything has been fine, i get alot of brown and hair algae, but its managable. Well, the emerald brittle star is starting to be a menace. He ate my banggai! Now when the lights are out I watch him try o get to me hermit crabs too. I feed shrimp pellets, frozen brine, and some small marine pellet type food by hikari. Why is my emerald star being so mean, and what should I be feeding him? (hes about 6 inches in diameter, if that helps. And my water is perfect as far as PH, AM, NI, NA, and salinity are concerned) Please help! - Thanks, Alex