too aggressive, i'm guessing.
my 55 has a breeding pair of nicaraguenses, a small red hump geophagus, 2 juvenile severum, a 5" african knife, and a chinese algea eater. please note i said african knife, not clown or black ghost. ive had it 8 months and its only grown an inch and a half.
the sev's will move to my 125 when they hit 5-6" but its not too bad right now. the nics keep the others out of the area they lay eggs in, but nobody gets beat up.