A couple of things that I would do differently:
1. Use a thicker piece of wood - like maybe a 2X6 for more mass
2. Make rubber "sleeves" for the screws that the 2X6 to the floor to go thru to further dampen vibration (small diameter rubber hose- like automotive vacuum hose)
I did not have either of these on hand yesterday and was too lazy to go buy them - maybe next spring. I'll likely be winterizing when I get back, prior to Nov.1, anyway.
My 5th wheel neighbor purchased a tank, but a little different than the Camping World one. He bought it at Lowes and the rough dimensions are 8"X13". It has a diaphram much like a pressure tank for a private well water system. For those of us not on city water, it even looks like a baby pressure tank; holding maybe a gallon of water. He said it helps a bunch, with the theory being that the diaphram absorbs a lot of the pulsing/vibration that would otherwise be transmitted thru the piping. He seemed to remember paying about $40 for it. I'm going to check it out on my next trip to Lowes.
Back to the sponge - I only tightened the screws enough to take the vertical "play" out of the wood. The only compression of the tile/grout sponge is due to the weight of the pump. The more compressed the sponge is, the more it defeats the purpose of the sponge. You'll still hear your pump, it's just less obnoxious.
If you hear some strange pump/sponge sounds on your scanner next spring...you'll know I'm busy with the upgrade!
