they require different pH's do they not.. im not really familiar with south american cichlids, but the malawis require a higher pH im sure
I mean I have had success with all of my fish which shouldn't be at the current pH.. did some acclimating, I mean its not natural (having them in the pH, african fish and south american fish), I will admit, but everyone is healthy and each one of my fish have spawned atleast once.
yellow labs are great fish, as are the johannis and bumble bee cichlids.. they all have a nice little personality.. mine really havent displayed any aggression at all but I am pretty sure they soon will..