Agreed, Pyramid B/F's are thebest bet, but I think mine finished off my small neon green trumpet coral. It disappeared shortly after adding the B/F, but I didn't see it do it or go near any other coral. I only had it a few months though. I've had my Copperband for7 months now and he doesn't bother anything. I don't have feather dusters or fan worms or he would have probably eatten them. I don't know about aiptasia, because I didn't have it. Just make sure if you get a Copperband it eats at the LFS and you can get live blackworms. I read that the Longnose B/F may be, but I've never had any experience with them. So, I'd have to say it would be between the Pyramid and the Copperband, but it's never a guarantee. HTH