I have hammer coral in a 20gsl. long for five years and it is doing great lots of new growth and babies. Equipment: 30lb live rock; power compact light 55watt atinic 55 watt day light; protein skimmer; hang on filter; power head; temp. 80-82; salt 1.025. I have had ocellaris in the tank at one time for about two years never hosted hammer. But ocellars are picky maybe other clowns may. Good luck