I use 4 40 gal barrels and in each one I use a weighted air stone and a heater. I have not had a problem with the water. I am on well water and my ph is always 8.4 . Even after aging the water it is still 8.4 so I let the ph along and I only age to get rig of the chlorine and the chlorine and chloarmines. I am on a community well so that's why we have the chems.