The filtration system on my Aqua One tank is a module that sits on top of the tank. Together with the lighting module they take up the entire top of the tank so there is no room for anything else.
I have 8 fish - Conspicuous angel, flake angel, pearlscale angel, cleaner wrasse, maroon clown, 2 perculas and longnose butterfly. Morph coral, elegance coral, maze coral, 2 anemones and a purple starfish. Feed is mostly frozen brine shrimp, blood worms, prawns, pippies, vegetable matter.
I live beside the ocean so I use ocean water which has zero nitrates.