Now I have, at least if you mean this one. I do not like the waste of disposable CO2 bottles, but the diffuser design is quite brilliant, well maybe you should tweak it a bit and do some math before hanging a bottle upside down in your tank, but brilliant it is!Have you read the forum on "old school" CO2 dissolution? Perhaps worth a try and easily removed if you don't want to pursue/go to full pressurised...