Overflow for 125 gallon

[saltypuffer]

I had a question about an overflow box that I will be drilling for my 125 gallon tank. I will be running a 40 breeder as my sump. I am wondering how many GPH on my overflow I need if my return pump will be 1200 GPH. From my understanding as long as my overflow is bigger (more GPH) than my return pump I’m all good? Is it possible to overdo an overflow/ Does this mean that I can buy an overflow box that’ll accommodate a much larger flow (2500 GPH) and still be able to use the same return pump, or is it a better idea to buy one that will be limited at less GPH? Any advice is much appreciated since this is my first build!

 

[lapin]

Better to go bigger. You want wiggle room. You can adjust the level in the overflow box with a gate valve. Its like a car. 2 seater only holds 2 people. 4 door SUV holds 4 or more but will also work if only 2 people are in it.