Thanks for the response. They are true union valves. Inlet is a 2 inch true union and outlet is inch and a half. The outlet, on the way to the tank - pass through a 1 1/2 to 1 inch reducer and then through another union. Does this look like it would work? My tank only has 1 - 1 inch center overflow. In the tank using loc-line I split this into two outlets.
Not sure what you mean by this statement "If the water is going to be falling from the fuge a significant distance I would put a bubble tower in the return section of the fuge instead." Do you mean if the water is going to be falling INTO the fuge a long distance from the tank? Or else, falling into the sump a long distance I should put the return into the skimmer section prior to the bubble trap? In terms of distance falling, everything is going to be under my tank in the stand (not customer made - acrylic. I can get the measurements if you need them.)