Size drain pipe

[rodgod20]

I am looking to push 300 gph through a sump. What size drain pipe?

I am thinking 3/4"

But an inch is more common, and I have limited space.

[MimicTang]

more is better then less

[bertoni]

http://www.reefcentral.com/calc/drain.php

That calculator might help. I get 0.75".