Too loud gurgling sound from overhead sump

[Piopips]

Hi guys. What can I do to stop the loud gurgling sound that comes from my overhead sump for my aro tank. Here's the setup

 

[duanes]

You may need to do a herbie drain, and drill another hole.
Below an explanation
How Durso, Herbie, and Bean Animal Overflows Work ...blog.marinedepot.com › charts-diagrams › durso-herbi...