I keep xenia, kenya trees, zoos, featherdusters and mushrooms with mine. The zoos were by accident (hitchhikers) because of the lighting they dont do as well. Xenia isnt stable enough for the horses but they enjoy the trees and gorgonians I have in there. I also grow caulerpa in the tank which they like also. These corals dont need flow or alot of light like most so they do great and the seahorses dont hide because of too bright of light on their tank. Carrie