I have a 13G glass sump that's drilled. I have a Little Giant pump who's housing intake connects directly to the bulkhead.
The pump motor is essentially silent, but the tank seems to make a very persistent "hum/buzz". It sounds like the pump's noise is amplified by the glass tank which in effect becomes a sounding box for the noise.
It's hard to distinguish whether the sound comes out of the pump intake or is produced by the slight vibration of the pump because of the very solid connection to the glass tank via the bulk head.
Would putting a section of rubber tubing between the pump intake and the bulkhead absorb the vibrations, or will they still be equally as loud?
Other suggestions on how to quiet the beast?