I’ve noticed a few times an asterina star on my single head of CB space monster zoa. Each time I pull it off and the zoa looks like doo doo for a few days then perks up. I wouldn’t say I have a star problem either. I’m not sure if they need more food or what. I noticed the one I do pull off has some color to it so I assume it’s been munching on other zoas too. How I’ve you guys taken care of these?