Help with noise in sump

[drknudsenx2]

I was able to fix my overflow trickling noise, and I widened the hole on the top of the Durso so for the most part that is pretty quiet besides mild noise of water trickling through the weir.
Now I’m getting what I think is the gurgling where water rushes through the piping and out into the sump. I’ve read a lot of threads and I’m still not sure how to go about fixing it. My pump flow rate is fairly low right now.

 

[lapin]

Maybe some hints in a thread like this one:

Durso drain noise reduction

Wondering if anyone can help me out with this. I have tweaked my durso drain to the point there is no noise out of the display tank side but I can’t seem to get the noise down in the sump.... any ideas?

www.reef2reef.com

"I’m don’t have a PhD in Fluid Dynamics, but i am pretty sure the noise you’re getting is due to air being in the drain line. Since the durso must be vented, the line will always have air in it, and will always have some noise. Velocity would just aggravate this turbulent interface between the air and water, but practically speaking it will always be noisy at any flows we’d care about in our tanks. The only way to evacuate the air is to convert the line to a full siphon w/ a gate valve, but then you definitely want that emergency overflow line in case of snails, long term buildup, etc. I suppose one alternative to the emergency drain would be to put a leak sensor with some logic in a controller to kill your return pump if the level gets too high. "

 

[Hypan]

I have used reverse dursos on a few tanks in the past to quiet it down a bit.