Clowns not getting along

Hi all. I picked up a couple of clowns in the middle of February, 1 is a picasso, and 1 is a snowflake, and they are about the same size. I knew they would fight for a bit to assert dominance, but they are continuing to bite at eachother almost daily and their fins are beginning to show bit marks. They are the only 2 fish in the tank besides a small scooter blenny. Does anyone have any suggestions or ideas as to how to fix this or will I just have to end up getting rid of one of them? Thanks! The tank size is 17"x17"x7" tall (was intended to be a frag tank). It is not a huge tank but they have plenty of room to swim and can easily go to their own sides when they want to.

 

They are both pretty small... 1.5" probably. I was really hoping they would be getting along by now, but it looks like I am just going to have to get rid of one and try something a bit smaller. I saw Sea of Marvels had a couple small picassos (i think), so maybe ill sell the snowflake and go pick one of those up.