Where to keep the overflow line?

[2Plus2]

Hi everyone, I have but one question.

Is it ideal to keep the gate valve dialed in to where the emergency overflow barely trickles in? I assume that keeps the water line the same all the time?

 

[MoshJosh]

Yes, the primary drains flow rate will be constant and controlled by the gate valve while the emergency line has a small trickle. In theory this should keep the tank as quiet as possible with no noise from air being sucked into the primary drain.

At least that is how I understand it. . .

 

[2Plus2]

Would drilling a hole where your desired line is a better solution?