Well, I have decided to go with two on the bottom, one row on top and about 1/3 the circumference. My wife does the shopping mostly and even though I was very specific about the charcoal that I wanted from a specific store, she brought me home blue bag kingsford. Should I make any adjustments because if this charcoal? I have used this stuff many, many times for high heat chicken, steak, and burger/dog cooks but never for a slow and low. It is all that I have so I will have to make it work.