Bean Animal Elbow help please

[Shawn7854]

I see absolutely no difference in having the secondary open in the overflow vs having an elbow with a hole? Please explain, the only con I see with the elbow there is no surface skimming but no benefit?

 

[BeanAnimal]

Explained in detail just a few posts back.

 

[Shawn7854]

Explained in detail just a few posts back.

I tried the elbow and if I increase the flow I hear the same noise in the secondary as without the elbow, example if I add a powerhead sometimes more water goes through the overflow like a wavemaker example or high flow uptop random and I heard water trickling “annoying” noise in secondary with the elbow + rodi tubing in the hole vs without elbow same noise, what am I doing wrong with the elbow to have it muffled?