I have been using the larger 2 micron stone and I do get some foam if I really open the oxygen valve all the way up. I usually just dial it back until the gas is barely coming through the stone so I get finer bubbles that just sort of coat the top of the wort rather than building up and filling the headspace. If anything happens to my current stone I would replace it with the .5 micron stone--I do have a very short lag time, but my oxygen bottles seem to go empty pretty quickly so I'm sure I'm wasting a lot of oxygen.
On tap:Witbier, American Stout, Imperial Stout, Root Beer
Bottled:"Massacreation" Chinook Barleywine, Belgian Golden Strong Ale, English IPA, Cabernet Sauvignon
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