Internal skimmer box into external overflow size adequate?

[B2Reef]

Spent forever re-thinking my 55gal tank setup from the stand up... I've designed my setup in cad as I go. I have the stand frame built minus the plywood and doors.

My overflow is going to consist of an internal skimmer box and external overflow box. Are these numbers okay for a 55 gal tank into a 20-30 gal sump?

Internal skimmer box: 22" long x 1.75" wide and 4" deep
External overflow box: 22" long x 6" wide x 6" deep
3 - 45mm holes connect the internal to the external box
Going with the bean animal with 1" pipes.
I plan to have the water level just above the 1.5" black trim edge. (Is this a good level?)

I don't have a return pump picked out yet but I have a few in mind, quieter the better. As far as a skimmer goes I think I want the Reef Octopus 110 Space Saver skimmer. With the sump I'd like a refugium not sure if I'll have a 20 or 30 gal sump under the tank... For now I'd like to get the holes drilled and glass siliconed and sprayed back black... then think about the sump. It's been a lot more than I wanted to do in all aspects, but I want this to succeed.

 

[ReeferBob]

Most 55s are tempered and not drillable. 55 is a bad footprint for a tank anyway. Take a look at 75s or better yet, 120 or 125.

Your overflow box is very long - are you going for a coast to coast style? You don't need three holes through the tank, 2 is enough. Maybe 2 1-1/2" holes. The external overflow only needs to be wide enough for the plumbing to fit into (bulkhead width). So maybe 2" or even less. For that size tank, 1" drains are more than adequate. I suggest a DC return pump I use a Jabeo DC-9000.

Carefully measure your holes and the overflows internal and external. Make sure the tank frame is not in the way of adequate room to have your water level just above the frame line. You water level will settle about 1/2" or so above the teeth in the internal box.