Really loud gurgling in drain line when pumps shuts off, any way to reduce it?

[Tac302000]

Hello everyone! I am running a 1.5" Bean Animal overflow which drains to my basement fishroom, about a 25' run. When the pumps (dual Iwaki's) are running everything is dead silent as it should be. My Apex is programmed to shut down the pumps during feeding so that the food isn't swept over the coast to coast overflow. When that happens, the noise from the overflow draining is really, really loud. The wife is not happy. I suspect there is nothing that can be done but I thought I'd see if anyone had any ideas for a fix. Thanks!

 

[Smokeshow]

I have the same sound but mine seems to come from the returns. not much can be done to stop it. its just air mixing in the pipes as the water level lowers

 

[windemerejack]

Why would you want it quiet? Its there to warn you something is wrong, if its quiet how would you know?

 

[Reef - Tripp]

You would have to adjust the return line valve to low level and readjust to normal operating level.

 

[Tac302000]

Okay, I figured out what I was doing wrong. I was adjusting the flow down the BA drain at my display rather than at the sump in the basement. I opened up the gate valve at my display and instead made the flow adjustment with the valve at the sump. Then I switched off the pumps. The noise at the display as the overflow emptied was now just a fraction of what it was before (because hydro science stuff I think). It still gurgles a bit (as would be expected) but it no longer wakes my neighbors baby and I no longer have to re-straighten the pictures on the walls. Thanks everyone for your suggestions!