Herbie drain clarification

[Mr. GoodStuff]

Currently have a 1” and 3/4” hole in the bottom of tank behind overflow box. Tank was originally setup with a durso but I’m changing to herbie using the two holes and will run a return over the top of tank with a DC controlled pump.

For the drains I’m assuming I should use the 3/4” for the main drain with the gate valve and the 1” for the trickle emergency drain correct?

Drilling the hole larger is out of the question as the glass is tempered.

 

[KStatefan]

That is what I would do

 

[NowGlazeIT]

That would be the safe bet, would work fine and better then the Durso too