[Visor]

   How much of a difference does it make using a .5 micron stone instead of a 2 micron stone and pure O2? I found a setup with the bottle for a very reasonable price, but it has a 2 micron stone that is welded to the wand and can't easily be replaced.

[Slowbrew]

I don't think it makes a big difference at the homebrew level.  I think I have a 2 micron stone and it works great.  I bought it several years ago and just don't recall exactly which one I have.

If my goal was an exact O2 level, the finer stone might be worth it.  The way I do it is basically, submerge stone, turn on O2 so I see it is working but bubbles don't break the surface and then let it go for 2 to 3 minutes.  Not really scientific but it works well enough.   

Paul

[mabrungard]

The larger pore size will be fine. As slowbrew mentioned, the important point is that you apply oxygen at a rate that is slow enough that the bubbles are well-dissolved by the time they reach the wort surface and there isn't any escaping the surface. It does mean you'll have to oxygenate longer, but it will be a better use of the oxygen.

Remember, you can overoxygenate your wort with pure oxygen.

[Robert]

Upside, 2 micron is a heck of a lot easier to clean and sanitize.  I use 0.5 for O2 and 2 to carbonate, just  because those are the ones that came with setups. Been thinking of going with the 2 micron for O2.

[Visor]

   Thanks for the input guys, Cheers.