help me with aux send & return

I want to keep a stereo signal all the way around, stereo going into the effect units (ie RE-20 and Sp303) and stereo back out of them and the 1604 returns. Do I have the setup below correct?

Mackie 1604 Aux Send 3 -> Space Echo RE-20 Left Input
Mackie 1604 Aux Send 5 -> Space Echo RE-20 Right Input
Space Echo RE-20 Stereo Output -> Mackie 1604 Stereo Return 3
-Control the volume of the return using the first yellow Aux Knob labeled "3-5"

Mackie 1604 Aux Send 4 -> Sp 303 Left Input
Mackie 1604 Aux Send 6 -> Sp 303 Right Input
Sp 303 Stereo Output -----> Mackie 1604 Stereo Return 4
-Control the volume of the return using the second yellow Aux Knob labeled "4-6"

http://www.zzounds.com/item--MAC1604VLZPRO

http://www.sweetwater.com/store/detail/RE20pedal

I'm sorry, the 1604 VLZ Pro doesn't have the yellow colored Aux Knobs, the VLZ4 version has got them though.

Nonetheless, the 1604 VLZ Pro still has the Aux Knobs labeled 3-5 and 4-6... they're right above the Blue EQ knobs. my bad