Africans (especially the ones you've got) are super aggressive and if they've not already picked on your tropical fish, probably will. And more than likely will kill them. African cichlids are highly aggressive. Because of that aggression and their eventual size require a 4 foot tank which is 55 gallons.
Not to mention the fact that cichlids and tropical fish have different water requirements. All in all, rehome (either get rid of them or put them in a different tank) the cichlids and you'll both ( you AND the fish) will be happier.
And yes, the dirt is poo lol