I am not saying throttle the overflow.
The tube shoved down will work. I cannot explain it any better then i have. (text sucks!)
When you fill that puppy up you will understand. the pvc glued in is not a problem, all i was suggesting is to drill a hole into the TOP of the 90 degree ell right above the tube that go's down to the sump. Thread a quick connect ball valve into the hole so you can adjust it for noise and flow.
I see Sas lurking. he's better at explaining then me.
