I'm new so take my opinion with a grain of salt but I have been adding one fish per 3-4 weeks let the bio filter establish the wait is killing me but what I remember from freshwater tanks add your small fish first let them declare their territory and get used to their new home (find the hiding spots) then add the larger more aggressive fish they have no need to run and hide just my opinion tho there are many way more experienced reefers here that will chime in