i believe its true in the case of some cichlids but not all, therefore saying all cichlids cannot be kept wtih anyting btu cichlids is totally untrue...i (and many others on this board) have kribensis which is a dwarf cichlid and i have 4 rummy nose tetras and 3 zebra danios in there, in fact its reccomended to have some tetras or something in the fihs tank to be used as dither fish. so to get a better answer find out what kinda fish you can keep in your size of tank and then see what works for you then ask if you can keep other fish wtih them, if you choose mbuna (im no expert) i believe its good to just keep them with mbuma