What Process Do Yo Call?

[aby]

If a process of water flowing from sump to the main tank is called by "return", what process do you call when water flowing from main tank to the sump?

 

[top shelf]

Drain line

 

[mcgyvr]

Drain line

Yep.. The water is "draining" from the display tank to the sump and the pump is "returning" the water to the display tank.

Drain (or could be called overflow too)

 

[Dmorty217]

+2 Overflow is what it's commonly referred to in the aquarium hobby. Also known as a drain