majano Oh boy .. I have had a friend who's tank was full of these.. Got one from a piece of coral and grew everywhere, Tried everything joes juice, kalk , hot water,butterfly fish, perpermint shrimp, the only way we were able to finally get rid of them was to take the rocks out with them on it and toothbrush them of under the sink. with running water..it took like 3 weeks of this process to finally get rid of them, and you still have to keep an eye on the tank..for more popping up.. Good Luck...