For haitiensus, Keep temp up, at least 80ish. And if possible, separate each into its own compartment with a cave to hide in, even when young they tend to want to kill each other., and will also try to intimidate each other, stressing each other into disease.
The 1st time I had them, growing out in 12 a 150 gal together, they all died in temps in the mid 70s. Second time with 6 they lasted longer in higher temps, but killed each other off with aggression, leaving the largest, alpha female.
From then on learning my lessons, they worked well.
If you have 4 or 6 in a 55 or similar tank, separate them with egg crate, and put a flower pot as a cave in each one, out of sight, no intimidation.
One other bit of info, just like they don't get along with each other, they also don't get along with other cichlids.
I kept my pair alone in a 6 ft tank, as adults they made the tank look tiny.
