Well, I took peoples advice, (cheers cichlidaholic!) and finally sorted out a one species tank!
I've removed the divider from the four foot tank...and it now houses all my yellow labs!
Aggression has gone down to zero, from now on I'm not going to mix species again, they seem to love being the only species in the tank, and aggression has turned into schooling, where they all follow the big male about the tank...
Here's a few shots:
Thats the fry tank above the main tank... I was wondering, whats up with my fry all being different tones of yellow? Is this normal?