Sizing and flow rate advice needed

[Twinanoreef]

For a 50G tank ( dimensions: 23.5” x 22” x 22”. 3/8” thick ), what is the better option for an overflow box:

1. 5.9 inch / 15 centimetres long overflow box with one drain pipe ( max overflow rate 3000 litres / 792 gallon per hour)
2. 11.8 inches/ 30 centimetres long with 2 drain pipes ( max overflow rate 5000 litres / 1320 gallon per hour)

Also, would a return pump rated as 528 gallons per hour be powerful enough for a tank of this size?

I am planning for this new tank but never had a sump before hence my question I would greatly appreciate your advice

 

[Quietman]

You'll get varying opinions on this...some like 2-3x turnover (how often display tank entire volume goes through the sump in an hour), some like 10x or more.

Personally don't worry at all about turnover rates. Any reasonable minimum flow will get you enough filtering to do the job on your tank. I just run something that's quiet, easy to adjust and keeps me away from the edge of spilling water. High turnover requires bigger pumps, bigger pipes which can be noisier and puts you closer to overflow (if not designed right) with a small sump (which is what you're going to have with a 50G tank).

It looks to me like either of those overflow boxes will work just fine (go for which looks better). I used a 500gph pump on my 40 gallon and was very happy with it.

 

[Quietman]

One safety tip here...if you plan on upgrading to DC return pump at some point....get an overflow that can handle max flow. Accidentally cranking up the flow and having water cascade over the tank sides won't be a pleasant experience.

That could just mean a bigger emergency drain and your primary drain is still sized for good control in the 500-800 range.

 

[Twinanoreef]

One safety tip here...if you plan on upgrading to DC return pump at some point....get an overflow that can handle max flow. Accidentally cranking up the flow and having water cascade over the tank sides won't be a pleasant experience.

That could just mean a bigger emergency drain and your primary drain is still sized for good control in the 500-800 range.

Thank you very much for the advice I really appreciate it.
I think I am gonna opt for the smaller version. Drain rate is 792 g/h and with a pump max flow of 528 g/h there should be no danger of overflowing. Also, the pump has an adjustable flow rate, given that the max one is already 10 times the volume of the tank , I can reduce it a bit if needed.