The nice thing about the Aulonocara sp. peacocks is that they are just about as tough as tilapia and breed quite fast. I've seen no issues with nitrates.
all of the cichlids are tough because of the rift river and lake system. there is no outlet, very alkaline, hard and poluted waters.
i spent several years involved with the pacific coast cichlid association in 80's and 90's when a lot of the africans were just being discovered and named.