I have a 7 inch female festae who has either been too aggressive for same sized males, or abused by larger ones. I picked up this 8-9 inch male 2 weeks ago and they have been doing very well. Right now they are alone in a 55 gallon and they are starting to show colors, and seem to be getting along well. I have a large clay pot split in two to create a cave environment. Any suggestions beyond that?