Bean animal question

[Ben Mccue]

I've been running herbie overflows on 2 tanks for several years now. The siphon line just has a screen stuck right in the bulkead of the overflow box.

I'm setting up a bean animal on my 180 and all the diagrams I see have the siphon line set with a 180 degree elbow arrangement with the open end about an inch from the bottom of the overflow box. Well there is one exception, brs has a diagram that shows the siphon line with just a screen on a straight pipe.
What is the purpose of doing the 180 elbows over just having a screen stuck in the bulkhead of the siphon line at the bottom of the box? Is that 180 bend necessary for some reason?
If it helps I'm using a modular marine overflow with the external box. Thanks.

 

[Peace River]

There are multiple variations on the original Bean Animal including a straight pipe, two 90s, two 90s with a small hole drilled in the top, two 90s with a small hole drilled in the top and an air line hose coming out of the hole, etc. My understanding is that much of this has to do with managing noise. I’m sure others will chime in soon with more insights.

@BeanAnimal

 

[KStatefan]

The original design was for use in a coast to coast overflow that was not very deep and had to have the elbows.



https://beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system/

 

[Ben Mccue]

Ok that makes sense thanks, so then I'm taking that to mean it's not necessary in my case.

Straight pipe on the siphon line means I can use the middle drain for the main which will make the runs to the sump on the other side of the wall much more simple in my case.

 

[BeanAnimal]

Ok that makes sense thanks, so then I'm taking that to mean it's not necessary in my case.

Straight pipe on the siphon line means I can use the middle drain for the main which will make the runs to the sump on the other side of the wall much more simple in my case.

The issue with the straight pipe is that it will be prone to creating a vortex and sucking air.... it depends on pipe diameter and flow vs depth above the pipe, but think of your sink drain or bathtub and how easily a vortex forms.

 

[Ben Mccue]

Ok well there's another factor. Somewhere between 1500 and 1800 gph turnover I think using dual pumps. I'm using 1.5" pvc for the drains. It's 6.25 inches from the top of the bulkhead to the inside rim of the overflow box. If it's a safer bet I'll just go with elbows. Thanks.

 

[Hal3134]

I've got a straight pipe with a strainer on it for my main drain. 1st emergency drain is a durso. 2nd emergency drain is an open straight pipe that I oversized compared to my siphon.