I built a 7' (yes, seven feet) by 4" cast acrylic skimmer in the 80s. Unless you like buiding things I think it pays to buy one. But if you want to know, just PM me with your contact info. It's not a venturi type but it wored great. I actually just bought a Reef Dynamics skimmer yesterday for my 55g. Maybe others have some better ideas.
Mojo, nice work!!! What size tank do you think that last one can handle? Have any CAD drawings or parts lists? I have access to cnc machines and lathes. Thanks, Matt