How did things end up? I had a similar problem with a 1.75" sheave and a 12" pulley, with the sheave spinning underneath a stationary 4L belt. After some reading, I realized that the most efficient power transfer for a belt pulley system is when the ratio of the diameter of the pulleys is 3:1 or...
According to WYeast's website:
"Some yeast strains have higher oxygen requirements than others. It is generally safe to assume that you need at least 10ppm of oxygen. 10ppm will supply adequate oxygen in most situations. Over-oxygenation is generally not a concern as the yeast will use all...
I was talking to a master brewer in Albuquerque, NM about aeration of wort, and I mentioned that I used an aquarium pump and a sintered stone. He told me that I should consider purchasing an oxygen tank to aerate the wort, because it is relatively inexpensive and does a better job of increasing...