Burping overflow driving me nuts

I have a 75G AGA with the "twin overflow" plus the derso styled AGA Mod. I have just rebuilt my sump to accommodate a new skimmer and hard plumbed the overflow tube with PVC. The overflow goes strait to the bottom of the sump and there is one 45 elbow at the end. Now I am able to increase the flow through the overflow but the more water running through the louder and more frequent the "Burping" sound becomes.
I have tried adding a flex airline tube down the overflow pipe but this does not seam to help unless I need a bigger tube or if I need to find the sweat spot.

Any help would be great

Thanks
Jason

 

Try a ball valve and slow the flow a bit

 

some times it takes a while til the pipes brake in (get some slime in them)
I had the same problem but after 2-3 weeks it got much better

 

O and another thing do you use a sponge on the back side of the overflow? I'm asking that because when I take mine out for cleaning I get the barbing noise to

 

OK I'll try the ball Valve. Dam that not what I wanted to do but oh well.

J

 

Whoaa.. wait a sec.

You have the pipe going underwater to the bottom of the sump? Why don't you just cut it a few inches above the water line and have it flow over a ramp or put a filter sock on it?

 

Ya I did that last night, Matt. Still Burps. But with the 45 elbow it is just below the water with out it is just above. Makes a hell of a splashing noise.
Something I have notice:
The "NEW" Mega (Derso) overflow pipe from AGA has been modified compared to the one I own.
Mine is a straight 1" pipe with the normal intake everyone is familiar with.
Unlike the Derso DIY type that would go from a larger sized PVC pipe and be reduced to 1" just above the Bulk head

The New Mega overflow with the mod has a section the is larger that 1".

Correct me if I'm wrong but if I was to add a section between the intake and the Bulk Head that was greater diameter than 1". This should slow the water enough for it to release the trapped water and get ride of the burping? Yes/No?

 

I think I was confused, the burping is coming from the overflow itself or the output in the sump?

 

The output to the sump. But it is excess air that is causing the burp.

 

How about having the elbow half way into the water?(so some air gets released )

If that doesn't work..

then add a tee fitting upside down so the air comes out of the tee and adding a couple inches of straight pipe after that? :-/