Overflow Plumbing - Advice?

[FranktheTankTx]

It's getting that time to start considering overflow plumbing.

I have 2 x 1" drains & 2 x 3/4" returns, all in the bottom of an external overflow.

What to do for a quiet fail safe drain?

[mcgyvr]

add another 1" hole and do a bean animal.

[FranktheTankTx]

Negative. Can't do that.

[FranktheTankTx]

Herbie still good?

[GroktheCube]

Herbie would be you next best bet! You could also use one of the return holes as a drain, and plumb the return through the single 3/4" hole. Running the pump through a 1" hole, and using the 3/4" holes for siphon and open channel, with the other 1" being the emergency drain would also be an option. I'd imagine two 3/4" drains could probably handle the flow.

What pump will you be using, and how much flow?

[FranktheTankTx]

Going with Ocean Runner 3500 (900 gph ability). I wanted to the return & run one line thru a manifold for (2) reactors (carbon & gfo).