Overflow box size ?

[tbub1221]

I've recently picked up another tank, its a 60 cube and its already drilled with a single 1&3/8" or 1&1/2" drain , I can't remember at the moment.
The acrylic overflow is home made , and although its put together well there are no teeth notches or holes and I think it will be less effective at surface skimming and probably noisier so im replacing it with a premade one .
My questions are how large to go gph rating wise , and is there any benefits to a larger or smaller or deeper overflow box.
I'm thinking about a jebao dc pump maybe 1200 or 3000 idk yet might even go with the 6000 for a future upgrade and run it on low , so should I just match the flow rate of the pump I choose.
And is there a formula I can plug my numbers in to to see hom much return pump I'll be needing.
Thanks for any insight , the world of sumps and overflows are foreign to me.

 

[tbub1221]

The drain bulkhead is 1 &1/4 but the plumbing goes down to 1" so that will slow things down a bit , is it sufficient ?

 

[northgahillbilly]

Is it just a single drain? If so 1" should be good for around 500 gph with a dorso from what I remember. I would probably re plumb it with the 1.25"

 

[tbub1221]

NorthGaHillbilly;1003784 wrote: Is it just a single drain? If so 1" should be good for around 500 gph with a dorso from what I remember. I would probably re plumb it with the 1.25"

Thanks for the reply , it is only the one bulkhead so I suppose I will look to increase it's diameter