Well, here is what we did. We had leftover pond liner, so I used that under the Mag7 - we still had the noise. After a lot of fiddling, cleaning & checking the impellor & casing, looking for any plumbing that might be running against the sump/fuge or the display, we finally realized that the SCWD unit was touching the canopy. After putting a mouse pad behind the SCWD, the noise has been reduced to a hum which is not very loud [hro Thanks everyone for your suggestions.