if you were two have 2 ore more clowns, i rec. you buy all 3 ocelaris at first and introduce them at the same time. ive tried to add a clown to a previously establish tank with another clown on the same species and they nipped at eachother all day. yet i have also kept a cinnamon clown with a domino damsel and a yellow tail damsel and found NO problems. a good method if you were to add another clown is rearrange the rockwork or take out your two clowns and add them all at the same time, always worked for me but i may be wrong