My New 72"x20"x20" Tank Build

[mark]

For the overflow glass, just take the corner off where it goes to the tank silicone.

Not to open this all up again but pls clarify, going from your drawing (and being your primary drain is blue and other that's above the 'n' in return is the emergency).

-You'll have a single gate valve just below the bulkhead and above the Tee to control the flow to the primary Herbie drain.

-A ball valve (as course adjustment okay) on the right leg after the Tee over towards the ref to control how much actually splits into the refugium (other leg, goes left dumping unrestricted to sump).

-The emergency drain line dumps, if needed, directly to the sump.