Ok so one lucky reefer's DC pump took a poop on them last night and they got to use one of my spare Jebao pumps on their system. I was told it was silent in their setup.
So, I went to work on my system and sure enough, it's how the pvc is held into place on the stand and how the pump is resting against the glass on the bottom of the sump. Once I pulled the pvc away from the clamp that holds it into place, it became a lot quieter. I then picked up the pump off of the glass bottom and it became very, very quiet. I didn't have much more time to play with it so I just put it all back as it was, but it definitely looks like I need to put some sort of dampeners in there somehow to quiet the pump down.
It's not overbearing, but I now know I can make it quieter so I have a new task to accomplish.
Curious to see what the unlucky reefer's pump looks like when it's taken apart???