any experience with banded and blue spotted SF in same tank

 Think I screwed up. I recently put  5 blue spotted sf in the same 40 gal breeder tank as 4 banded sf. The banded sf are larger and the dominant male, killed the dominant male blue spotted sf. Even the female banded sf are acting aggressive towards the blue spotted sf.         The blue spotted sf are doing what they do best, hiding. I thought the two spieces would get along.  Tank too small ? Recently moved the banded sf from a 40 breeder that housed them, 5 blackskirt tetra (a little larger than the blue spots), and a flag fish.  Any thoughts ? 

How big are the banded? If there is a size discrepancy then weve probably found your answer. Your blues are still small if they arent as big as your tetras yet.

What sort of tank-setup do you have? The more heavily planted (and structures/places to hide) the less chances of aggression.

Seniority might be more important than size.  Established sunfish will usually attack newcomers.  A screen divider for the first couple weeks might help (no promises) so they can get used to the sight and smell of each other without physical contact -- similar to cichlids and other territorial fish.  

ok, thanks I'll try that