The filtration unit is usually the most expensive piece of equipment for a tank. For a tank that large, you're looking at $150 to $200 for filtration. The larger tanks should really have two filters so the water is equally filtered.
Put a backing on the tank to cover up any tubes and wires. That way you don't see any of the filter stuff. It will take longer to cycle the 120 gal
tank. But it is easier to maintain water quality. That's whats so great about these large tanks. When my fiance brought home the 150 gal
tank, it was quite intimidating. Considering our largest tank was 55 gal
. But they really are easier to maintain and keep clean.