actualy this could be one of those cases where it could be both.if i remeber correctly.it depends on what book you read or how old the book is.i will try to find where i read about this so i can clarify.
Hrmmm... hah hah well I got the right one from somewhere. Regardless, that guy seriously knows his stuff. Hit the contents and go to setting up a simple Convict Cichlid aquarium.