I used the oxynater for the first time today. I hooked it up to a small disposable oxygen tank. The instructions say, boil stone for 20 min before & after using, place in wort for 15 seconds then let the foam settle and repeat. Well aside from oxygen coming out of the stone there was no foaming at all on top of the wort. I was expecting a volcano like reaction in the carboy. Does the beer style or the small disposable tank have something to do with this?