Overflow box

Please help me silence this aqueon HOB overflow I can't take the noise

 

Pictures please...and a little more info ! : )
I went through this issue on my 55 a few years ago...many options depending on what is actually occurring.

 

Have you built a durso yet?

 

It is an aqueon model 220 HOB overflow with a double "U" tube. Ok so my setup is on the overflow I have two drains a ball valve on each going to 3/4" tubing to a tee on the muffler on the sump my return is with the head room 425gph on a 75 gallon tank

 

I could use a pic, it would help a ton. First thing I see wrong is you don't want valves in the drain side, it's a recipe for disaster. What kind of noise are you getting?

 

It sounds like a flushing toilet