Help with noisy over flow drain

[Robba456]

I just purchased a aquatop 40g reef cube it has a internal corner overflow single pipe with a 90 and a single air hole in the top for siphon break it is extremely loud down in the sump sounds like theres alot of air coming down with the water i tried raising water level in tank and sump i tried putting a please for foam at the bottom of the drain in the sump anyone have any suggestions? There is no ball valve to adjust the flow either.

 

[Biglew11]

Slowly make the hole in the drain pipe bigger. The small hole in the drain is probably creating a partial siphon bringing lots of air down to the sump.

This is a durso style drain, do not put valves on the drain.

 

[ATB USA]

sometimes a 4: hose in the air hole will silence the sound

 

[Brady4000]

Slowly make the hole in the drain pipe bigger. The small hole in the drain is probably creating a partial siphon bringing lots of air down to the sump.

This is a durso style drain, do not put valves on the drain.

+1 @Biglew11 this is probably the issue.

This is the exact drain I have. Also are you draining into a filter sock? Do you have the pipe below the water line like 4 inches?

Mine was loud in the sump when I had it only about 2inchs under the water line.

Edit: Mine is still loud in the overflow, my next project is, I am going to be making a Hofer Gurgle Buster. Might be worth looking into. I can’t comment on how well this works yet because I don’t have one. But gives you more options to look up.

 

[Robba456]

I was not goin to put a valve on the drain i was just explaining what it was i have. And yes its draining into a filter sock, and yes its about 4 inch or so into the water. Im goin to try making the air hole bigger i have seen others that have had this problem do so with success thank you all.