I bought this actually small device (acc. To instructions for aquariums up to 40L) for my 120L aquarium. However, not to filter the water of this aquarium, but to provide a cost-effective additional oxygenation of the water, because the permanently installed inside filter did not allow a great change in the water effluent. The Trixie filter has several components for Ausströmmöglichkeiten. I have chosen, in the above the water surface, a plastic tube was attached with several holes. This causes the water like a small waterfall flows back into the aquarium and ensures a good enrichment of water by O2. The pump runs extremely quiet, the fish enjoy the new Wasserverwirbelung clearly and cavort over again in the whirlpool. I am fully satisfied.