my opinoin
i actually have quite a few peaceful malawi cichlids right now.yellow labs,rusty cichlids,blue dolphins,red peacocks and yellow peacocks,and frontosas from lake tangerine or whatever(cant remember how to spell it)i can put anything in that tank as small as an adult feeder guppy and not one fish will attack it.though i once put a juvenile red devil in the tank he started a fight with my dominant male yellow lab and got his butt kicked by every fish in that tank once the yellow lab smacked him around they all went after him.had to rescue the red devil...anyway ive also been told that aroura(sp?)cichlids are very peaceful and im looking to get some,but cant vouch for them yet.for the record only the yellows and rustys are big enough to breed.the dolphins are 4" or under and the biggest front is about 5" there is also a 1.5" - maybe 2" black belt in there with them,a 5 inch pleco and one lonely cory cat.i have kept guppies,chocolate cichlids,young oscars,baby- jack dempseys,convicts,green terrors,firemouths,dinosaur fish,clawed frogs and snails in the tank and the africans have never ever bothered another fish,except the red devil who bit off more than he could chew,oh and the smallest front chased a very young sunshine peacock nonstop just that one fish and never did figure out why since there were two other sunshines in the tank and the front left them alone.this is just my experiance with these few species ive worked with. hope that helps.oh and alot of books will tell you that bumble bee cichlids get to about 4 inches and are peaceful.there full of @#%$ ive seen em 6 inches and smackin the crap out of alot bigger fish.