Overflow Sizing

[appleton71]

I'm in the process of configuring a 240 gallon tank to be built by customaquariums.com and I'm trying to decide which of their overflows to use. My pump will be 3,200 gph at 0 head and about 2,300 gph with my head loss (basement sump). Their 2,400 gph stealthbox seems like the right fit but would it make sense to upsize to their 3,600 gph unit for an extra $80? I know I'll never be flowing that much water through it but I see two possible advantages: 1) if a screen was to get plugged, there are two more to take up the slack. 2) more surface skimming area.

For those not familiar with the stealthbox, here's a picture of the 2,400 gph unit. The 3,600 gph model has 3 intakes.

Opinions?

 

[Yoimbrian]

I’d go with the bigger one, for the reasons you said.

I’d also confirm your pump math. Head loss on a pump is not only vertical height, but also length of tubing, bends, outlets, etc. going 15 feet vertically you’d likely be 25ft or so head loss - assuming you do large enough pipe and minimal bends (more if you don’t). If I had to guess a pump that did 2,300 at 25ft does more than 3,200 at 0 ft.

 

[appleton71]

I'm using 1.5" spa flex for the return so I won't have much for fittings and it's only 8ish feet vertically. The pump will be a Sicce Syncra HF 12. I'm currently running an Iwaki on my 125 gallon that only does about 1,100 gph at 0 head with 1" spa flex and it works fine.

 

[Yoimbrian]

Well, in my opinion you won't get nearly 2,300gph under those conditions, but who knows. Let me know how it goes!

 

[appleton71]

Luckily I don't need that much turnover so I think whatever I end up with will be fine. It'll be a while before I have the new tank set up. I'm only in the planning stages and there's a 14 week lead time on the aquarium.