I have a 180 (6x2x2) with a 40 gallon wet/dry sump and twin 2217 Eheims. In the tank is a 8" Tigrinus. He's a beautiful fish but boring as Hell. Rests all days, plays all night. I'm wanting to add a 12" Black Aro. Is my tank big enough for one for life without having to upgrade? I've got mega filtration and lots of flow with 2 Mag 7's returning water from the sump. Is this an ok sounding tank for these two fishes???