I've had three orange chromides in a 20 long they did fine but they can get aggressive
make sure they are all about the same size.I 've never seen one grow out more than 3 and a half inches they can do well with any low end brackish fish .Green chromides would be a great tank mate (the orange chromide serves as a cleaner fish for the green chromide in the wild ),but good luck finding them I searched for quite a while with no success.Try to get a half dozen @ about one inch
and see if any naturally pair off over time(since these cichlids are so hard to sex at any stage in thier life ,buying this number gives you a good chance at getting
a female or two.)I know tons about this fish so toss me an email if you have anymore questions.
I have got orange chromides with some monos, eels, shark cats,knight goby and also a pea**** goby.I don't find them too aggressive.only when they have spawned and are protecting the young.
what sizze is you tank in inches?