Reef Ready 90 Gallon - Overflow Plumbing Question

[Ric878]

Hi,

I have a reef-ready 90 gallon which has the overflow in the back right corner. Inside the overflow, there are two pre-plumbed holes, a one-inch and a 3/4 inch. I assume the original intent was to use the one inch as the stand pipe and the 3/4 was the return. I of course am concerned with not having any redundancy in the overflow to the sump. I figured I would use both in a Herbie setup and then run a length of PVC up the back for the return.

Questions:
Does this seem like the right course of action?
Which of the two existing holes should I use as the primary? The one inch or the 3/4 inch?
Any other ideas or alternatives I should be considering?

Thanks,
Ric

 

[Tuffyyyyy]

I think you're on the right path. I'd use the 1" as the primary and the 3/4" as the secondary.

 

[Snoopy 67]

Depending on water flow here as to which is which
https://hy-techroofdrains.com/water-flow-through-a-pipe/

 

[Ric878]

Would it make sense to use an adapter to increase the 3/4 inch bulkhead to one inch? Would that create a bit more pressure?

 

[KStatefan]

I would use the 3/4" as the primary and the 1" as the secondary.