Overflow Plumping making a lot of noise

[bk_market]

I recently set up a new 83 gallons tank. The overflow is making a lot of noise from the air hole on top and splashing water sound in the sump. I think this overflow is call Herbie.

I use a sicce 3.0 as a return pump and the only way I was able to somewhere reduce the noise was to slow the return pump by releasing some of the water back into the sump/refugium.

While this help with the noise, I feel like I have redirected 75% of the return line back into the sump and the flow to the sump from the main display is not enough.

I am not good with plumbing anything so hopefully you guys can help me out with some solutions.
Should I drill another airhole on the overflow? There is one on it already. Would that allow me to have the return pump move more water without making a lot of noise?
Let say another additional airhole solve the sound on the overflow, how do I deal with water splashing sound in the sump if I incease the return pump flow?

Thanks.

 

[Crabs McJones]

Any pictures of the plumbing setup?

 

[Instigate]

If you have your drain pipe submerged below the water line it will quiet the splashing. I plumbed mine so it is just above the sock then added a little extension to get below, but I didnt glue it to make changing filter socks easier.

 

[bk_market]

I do have the drain pipe about 1" below the water surface in the sump. I can hear the air bubble out from under the pipe when water goes through it. Though I hear a lot more noise from the air hole on the top of the overflow pipe in the display tank. It like whistling sound through the hole.

 

[Vahanyos]

Try reducing the return pump gph without using a drain to your sump. I'm running about 300gph up 4ft with only the JTube for head loss and my noise is quieter. Got plenty flow in the sump too. I'm thinking of going slightly less to really quiet it down. Search for some videos on YouTube also lots of ways to reduce the noise