Diffusion Stone aeration

I'm stepping up my game. I used to not aerate my wort without any sort of pump. Just stirring with a sanitized theif, or shaking. Never had a problem. On my last trip to my LHBS I bought a 2 micron diffusion stone. It was cleaned, and used on a small aquarium pump.

To my question. Will the 2 micron make visible bubbles? I didn't notice anything while using it. Is this to be expected/ too weak a pump/ leak in my air line?

I use pure O2 with my air stone, that was purchased from Williams (so it's also on the stainless wand), and get a good deal of activity in the fermenter when pushing O2 through it. Not sure how much you'll get form a pump, but you will be limited as to how much PPM of O2 you can get that way (it's a limitation of using the ambient air).

I hope you have the sanitized filter in place before the stone, to catch any bugs that could get pulled in. Which is another thing I don't need to worry about when using pure O2...

If you blow into the tube can you make bubbles? If not you have a clog or leak.

Have you boiled your stone? It may have been handled before it reached you and the oils of folk's hands could have blocked the pores. A 15-20 minute boil is recommened before use and after every few uses. Additionally, are you cracking the regulator all the way open? Some of the brands and the older models (like mine) have only 2 settings, closed and cranked all the way open, there's no mid range on many of the cheap o2 regulators. The only time I get any activity or bubbles is if it's cranked all the way open.

He is using a pump not a tank/regulator.