Bean Animal With External Overflow Bulkhead Size?

[Kelesco]

I would like to set up a coast to coast bean animal with external overflow box on a 120g tank. I have found for an internal overflow you can use 1.5" pipe, reduce to a 1" bullhead through side tank, then back to 1" pipe. My question is does anyone know if you should still reduce the bulkhead to 1" if goes though the bottom of an external overflow box? If I'm going to go though all the effort and expense of setting this overflow up I want to make sure I at least get the bulkheads correct so I don't have to drill the glass twice.

 

[zoomster]

I have done a bunch of bean animals now including my new 120g.
I have always gone 1.5" all the way to the sump with a 1" "street elbow" right at the start. ( which is how the original Bean animal design says to do it. ) and believe me, it is the best, I love the bean animal!
I would highly recommend drilling and installing 1.5" bulkheads. You can easily reduce down to 1-1/4" or even 1" but it is much, much harder to drill bigger!

 

[Kelesco]

Thanks Zoomster. Does Seem like a better idea to put the bulkheads in 1.5". I don't know why the design I saw called for a smaller bulkhead for a internal overflow.

 

[shamous113]

I did my tank with a internal c2c and a bean animal external overflow running to a basement sump. I did 2 - 2 3/8 holes thru the tank to the external box all plumbing is 1.5". With 8' of head i'm pushing 1200-1300 gph and I only have the valve open about 1/5th of the way. Some people end up with smaller plumbing because that is what their tank came with and others go smaller because the aren't pushing a high volume thru their sump.

 

[zoomster]

I did my tank with a internal c2c and a bean animal external overflow running to a basement sump. I did 2 - 2 3/8 holes thru the tank to the external box all plumbing is 1.5". With 8' of head i'm pushing 1200-1300 gph and I only have the valve open about 1/5th of the way. Some people end up with smaller plumbing because that is what their tank came with and others go smaller because the aren't pushing a high volume thru their sump.

True but I was advising him based on Kelesco's set up.
It is also easier to go bigger and "throttle back" than to max out smaller plumbing and curse yourself for not going bigger when you could have. I believe in always thinking ahead ( like getting a stand big enough for a 180 when my new tank was only a 120 )

 

[shamous113]

I totally agree bigger is better, I've had a Mexican turbo go for a ride down my main line thank god he was smaller then then the plumbing so I was able to get him out with out cutting the plumbing. If I were to do it again I would add another hole thru the tank to the external overflow,its borderline IMHO for the volume I'm pushing thru my system even though the calculations said it was good.