just a suggestion, but iwould add one amaller than the one you have, and also make sure it is not the larger more dominant in it's brood in the store also, just to insure that it is a smaller male, it is likely that if yours is not a female, that it will then become more dominant and be come the female, this is just incase, with clowns you can have 2 males the larger more dominant will become a female, but 2 females may possess a problem
HTH