plumbing question

[RichE]

I have two pumps that are 650 gph but the question I have is the outlet hole is only 1/2", so if I was to use these pumps in my sump I have about a 4ft run to the top of the tank. Should I connect the 2 pumps and run into one return or should I make 2 separate returns.

Also is 1/2" pipe going to be ok for the whole run or can I up size it to say 1"?

[lilscoots]

I'd run two seperate returns, and upsize them
 

[RichE]

I'd run two seperate returns, and upsize them
 

Thanks