So far so good. I don't have any serious aggression issues except for a 2 second chase here and there. If anything, my algae eaters harass my Africans and are the usual suspects/cause of sand being stirred up. I have a 3200 GPH wavemaker on one end and a 1600 GPH wavemaker on the other. I really think that having a strong current running both ways keeps my fish swimming and happy, so that they don't get bored and get any crazy ideas. I used to have a small Red Devil, but rehomed him because even though he was small, he was very aggressive and would always stir the pot. It seemed that his aggression alone spread throughout the tank and raised my other's aggression levels as well. This setup has been achieved thru trial and error, but I seem to have found a balance for the time being. It is a well know practice that by keeping an African cichlid tank heavily stocked even overstocked, it doesn't allow for one fish to become dominant and allows for "controlled chaos". I have kept Africans in the past and wanted to adapt this method to a varied species of fish and it seems to work. As far as the puffer, it seems that you need to find the right size puffer. I have bought smaller ones that got picked on and then I tried a Fang's (Red Eye) puffer which was a total disaster as it chomped off the fins of any of my curious cichlids, even going after my much larger managuense. So I finally found a 3 inch FAT GSP who is not really aggressive (compared to the fangs) and big enough that my other fish don't bother him one bit. And he has never nipped at his tank mates. But, many of my fish have some growing to do...So what works today may not work tomorrow. I take it on day at a time.
-When I picked up my female Nic, she was already colored up like that. Couldn't believe how beautiful she was, had to have her. Good deal at $24.00 US