I have Congo and Penguin tetras together in a 80gal cichlid (dwarf and juvi angels) community tank. I find that the Congos pick on the Penguins. It's not over territory or breeding as they allow other peaceful fish to school with them. Anyone have any experience mixing the two? I'm wondering if I have too few Penguins (5). I put them in my tetra tank and they were absolute bullies with the rummy nose. Thoughts?