I have an MP20W running on a 70 gal & it's fine. The flow may be fine tuned to suit your needs so you can dial it down to half speed if you like, it should run quietly and cool at that setting. If I'm not mistaken the physical size of the MP20 will be the same?? So your not saving any visual clutter by using an MP20, plus you may have to run it at maximum speed and it may run hotter?