Q-A - there was some movement of the top plate, but not much. Its either 3/16" or 1/4" thick aluminum plate. Still, good idea to look at. I did place a tool against it to try to get it to suck in enough air to drop out of syphon mode to no avail, and the noise did not stop when I had the bar against it. Should have put my foot on it. Its worth stiffening the new larger plate with a couple strips of aluminum angle. Maybe place some rubber between the plate and the pipe.

Jake - its PVC pipe that has been painted brown so its UV protected and also not a white eyesore. The plate has been painted brown also since the photo was taken.

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