Hi ChknWing,
Its loud in the sump where the drains empty. The drain line and overflow box/stand pipes are actually quiet. The tank was predrilled with 2 corner overflows. There is no noise in the overflows except for the occasional sound of sucking air in the air tube that goes into the stand pipe. I used Durso initially and am now using stand pipes that Frankie gave me. Its an end cap with holes on the underside on top of the stand pipe but there is no difference in the sound between it and the Duros.
Here is where the noise is at. Bubbling sound I think best describes it. I have put filter socks on them and that has reduced the noise some what but it still is loud and irritates my wife.
If its the intake, what can I do to rectify it? Thanks.