Overflow dimensions

[mark]

Thinking about this on the drive in from work.

Consider a single 12" diagonal overflow in the corner with 3-1" bulkheads. Laid it out on paper but since at work don't have a 1" bulkhead in front me so guessing on footprint for nut and flange so might be able to go smaller. The bulkheads would be drilled 2 on the diagonal face, 1 in the back corner. 2 of the bulkheads, vertical standpipes for Herbies (primary and emergency) third bulkhead for return.

With this the 1" return allows less restriction, the Herbie give a silent overflow with a backup drain.

[mr_alberta]

There is no way you could run an external overflow (and I don't mean an external overflow box like a cpr)? The next time I build a tank, that's what I would do. That way you maximize the area inside your tank.