Holes and Bulkheads

[PJSea]

Is there a guide to how much flow a certain hole can pass? I am looking to get a glasscages 120 gal. tank. They say their 1 1/2" drain wll pass 1500 gph. Assuming they meant hole size, I question whather it will actually pass that much flow. Almost all other guidance I've seen says it is about 600 gph max.
How many holes and what size would you recommend for sump/refugium setup and possibly closed loop. I'm looking at Aqua C EV180 with Mag 9.5 or 12 as a return. Haven't decided on pump for potential closed loop yet.

[Ninong]

If they called it a 1-1/2 inch drain, then that's what they meant. That's not the size of the hole. The size of the hole would be much larger (2-9/16"D for most Sch. 40 bulkhead fittings, slightly larger for Sch. 80 fittings, but I'm sure the tank builder knows what size hole to drill for their 1.5" bulkhead fittings).

Yes, 1500 gph is a conservative flow estimate for a 1.5" drain. My 120-gal tank had a single 1.5" drain.

[PJSea]

Thanks for the input

[Steven Pro]

I put three 1 1/2" bulkheads on my 120 for drains to accomodate quietly the return flow from two Mag-Drive 1200's. These holes were drilled in the back wall with a Calfo-style overflow box.