An overflow box and a filter system for an aquarium are disclosed which quiets the removal of waste water from an aquarium. The aquarium has a bottom wall, a sidewall, a first aperture formed through the sidewall, and a peripheral rim. The overflow box has a bottom wall, a front wall, a back wall and two sidewalls. The front wall has a first opening formed therethrough which is coaxially aligned with the first aperture formed in the sidewall of the aquarium. The bottom wall of the overflow box has a plurality of slip fittings formed therein. The plurality of slip fittings are of at least three different sizes. One of the slip fittings is open to water flow while the remaining slip fittings are initially closed to water flow by a thin wall. The overflow box also has an open top.
