It's a bit much bio-load wise for a 125gal. The Oscar alone is a big bio-load for a 125gal. Don't know if you have seen them at adult size, dropping pencil size poo 3in plus in length. At five years this lady was pushing 14in plus. Oscar's don't stop growing they just slow down.
I would drop the Zebrina as they get bigger and will add to the bio load along with the chit factory of the Oscar or maybe replace the Oscar with a Chocolate Cichlid
I would drop the Zebrina as they get bigger and will add to the bio load along with the chit factory of the Oscar or maybe replace the Oscar with a Chocolate Cichlid