[mike31154]

Check the first photo of my post #18 in this thread. That air diffuser was doing its thing for 6 months if not longer and still producing better bubbles than any brand new store bought wooden diffuser. As you can see, the wood grain is starting to open up quite a bit so sanding or anything else is not going to extend the life of one of these. When I was using the store bought diffusers, I once soaked and boiled a few of them in a vinegar solution in an effort to get more life out of them. The performance wasn't that great after that, but I was able to use them a little longer.

For my skimmer I don't need a piston air pump, the Rena Air 400 diaphragm pump is more than enough and along with the small AquaClear 301 powerhead, you can barely hear a thing. My lighting fans and VorTech pumps pretty much drown out the low hum produced by the Rena.