Have a new smoker with sfb. I lit the lump charcoal and put it in. I cant get it to 220. How much should I use. This is driving me crazy. Do I have to put in a whole bag. I am getting to the point were I may throw it in the ocean. The vent is set at 3/4 open both side and top. I put one oiece of oak in it. Pleasssssssssssssssssse help.