75 Gallon drilling

[lockecole]

I've got an AGA 75 gallon tank that i'm getting drilled(on the back). I would like to run about 600-750 gallons per hour, would a 1.5" bulkhead be sufficient due to having to run 2 90 degree elbows, 1 on each side of the bulkhead. And with a 1.5" bulkhead what size would the hole be?

[Ron99]

I have one bulkhead on my 75 and had a hell of a time getting it to be quiet. I would go with at least 2 bulkheads to set up a herbie system instead of trying to drain through a single bulkhead. That being said, I did manage to set up a pseudo herbie arrangement that is fairly quiet.