Tanks look great. The AC"S are great for power but for biological you can't beat an emperor. The Emperors style is a small version of whats used at commercial fisheries and sewage plants. These places use huge "Rotating Wheels" called RBCs (rotating biological contacters) to deal with heavy amounts of waste to be broken down biologically. The bio-wheels used by Marineland are the little versions but provided the same effectiveness. Bacteria on these wheels can breakdown upto 30,000 times more waste then the same bacteria submerged in water( all other conventional aquarium filters). The reason for this is that there is 30,000 times more oxygen in air then water, so the "di-nitrifying" bacteria can work much more efficiently then the same bacteria sub-merged in the water. This is what makes the bio-wheel so good over all other aquarium filters.