Answer:
You may need to buy a bigger tank. If it is big enough is there places for the Cichlids to escape to or hide. The way that I got my Cichlids to stop fighting is to overstock the tank. You will need a really good filter, a big one, to handle the load of all of the fish. Ask somebody at a reliable pet store how many fish you should put in to over stock.
I hope that helped :)
PS: don't ask anybody in wall mart's fish
department, they don't know anything.
PSS: If you tried that and they are still a little aggressive you
can try a veggie clip. You can put vegetables on it and they
will eat off of it, ask somebody at the pet store what things you can
put on it.