Use this 2 micron stone with an oxygen source or an aeration pump to provide your yeast with oxygen prefermentation. This diffusion stone can also be attached to the end of your “gas in” on your keg with 50cm of tubing to rapidly speed up carbonation. CLEANING: This stone can be sanitised in boiling water and cleaned in anon-rinse sanitiser while running CO2 or air through the stone. If the pores in the stone get blocked from handling give a 10 second dip in hydrocloric acid before rinsing with water.