Zoanthids and Palythoas make for great colonial polyps that add a ton of color to a reef tank, but occasionally they invade the space of other corals. The polyps will grow up the hard skeletons of many LPS corals, around the bases of SPS colonies, and even on the walls of the aquarium. While these fast growing polyps don’t typically disturb other corals, they can inhibit the growth of those corals in certain directions. Whenever the Zoas and Palys grow, they lay down a thick mat of tissue. This tissue will prevent other corals from spreading out, although not a whole lot of corals will be able to stop the polyps from taking over.