Yes it should get adequately aerated when going through an overflow or the diff levels off a sump or out the return. The main problem I thought of/was adressing was if the torpedo had a designated sole purpose pump and return line both of which were under the surface. If this was the case then at night you could run into problems with low DO. This is because the photosynthetic algae that produces O2 during the day actually respirates and uses up O2 at night thus possibly putting your tank into a low DO situation if the returns weren't adequatley oxygenated.