I kept mine with a Nile perch of around the same size. I also kept 4 huge giants danios in the tank with him to school with as it calmed him down and made him less likely to spaz out. Goliath or Vittatus it really doesn't matter, they both get huge, way too big for a 225. It needs to be the first in the tank and can't have any tankmates that can even be slightly intimidating to it until it hits the 10 inch mark IMO... I am 17 and still live at home and my mom isn't thrilled about my tank either but my dad likes it so it stays.