Plumbing Help

[buffalo_dives]

Can anyone tell me the best way to run the plumbing? I have a Glass Holes 1500 overflow that has 1 1/2' drains but my Eshoppes sump has 1". So should I reduce the size at the overflow or increase the size at the sump?

 

[Owensue]

I would reduce it at the overflow if it's a drain, at the sump for a return (less head weight).