use both pumps as return, you could even goi get a couple other pumps instead, like two little giants or iwakis love the lights
beautiful piece of wood by the way
I'm actually thinking I'll use one for the return and one for a closed loop, and run the co2 through it. I need to see if I can mod the eheim for a needle wheel or something. I heard there is one that will fit from another pump, a Sedra or something, but I'm not sure which.
It's actually 15 or so pieces!