Thats a fairly small tank and youre probably not seeing many pods because of the Manderin. Any extra realestate that can be used for pod propogation is a good idea and a refugium serves more than that purpose, its also a place to grow macro algae for nutrient export. Removing the bio balls slowly over a period of time is recommended, you can always exchange them for good, established live rock rubble. Refugiums are a whole worl in themselvs.