Remove the grammy for a day or two (if possible) and rearrange all the scaping. leave the new dithers in there. I recommend small convicts (male) and silver dollars. Throw him back in a few days.
This will give the grammy less to get worked up about. I do it all the time when introducing milder fish to a very dominant fish.
This will give the grammy less to get worked up about. I do it all the time when introducing milder fish to a very dominant fish.