I currently have a 120 (4x2x2) with a Mag 9.5 in sump (had a Mag 12, too much flow) and two Koralia 3s in the display. I have the returns from the sump split with two going out into the tank and two aiming down behind the rocks. I would like to have an additional powerhead down behind the rocks to try and keep from having dead areas but don't want to see the wire going down in the tank. So i am considering putting a Vortech mp20 behind my stack. Any opinions? Thanks.