In my experience with grammodes for close to a year now is that a divider makes their aggression towards the fish on the other side worse. My pair was divided from my istlanum and all they wanted to do was get had him and when i had my other grammodes divided from them he some how got to the other side and the pair destroyed him. I sold the istlanum took the divider and introduced dithers wiith only 2 out of the 5 getting killed. After keeping dithers with them i started adding some new cichlids and right now i keep a geo, pike, and red devil with my pair and they are fine now. My grammodes are fed 3-4 times a day to keep them full and i keep my temp at 77 and it seems to have calmed them down some. The are called the mini dovii for a reason and i strongly believe if they were able to grow a lil faster and a little bigger they could be a top predator cichlid.