To which height should I adjust the outlet of an internal filter?
Should I adjust the water outlet of an internal filter below or above the water surface? And how do I make sure enough oxygen gets into the water?
there are no firm rules, both is possible. Adusting the filter outlet also depends on the fish that you keep. Labyrinth fish, for example, require slow water currents, not only at the surface, whereas it should be very strong for surf zone dwellers (e.g. Tanganicodus, Eretmodus and Spathodus goby cichlids from Lake Tanganyika). The sera internal biofilters B 200 and B 400 therefore even provide alternative possibilities for placing the outlet.
A water outlet at surface level is recommended for most situations. It is well agitated when doing so, but there will be no splashing noises yet.
Dr. Bodo Schnell