I noticed that without my plate setter, my vent openings are next to nihil to keep a slow and low 250 degree temp. With the plate setter, my bottom vent needs to be a quarter of the way open to attain and maintain the 250 degree temp, which I assume affects the rate of burn of the charcoal. Maybe I am not patient enough letting the dome get up to temp. My 5.5 lb brisket took 7 1/2 hours and my charcoal was 3/4 gone and spread out so maintaining a 250 degree temp at the end required me to take off the daisy wheel and open the bottom vent full boar. After the cook, I raked the ash through and piled the remaining charcoal let her go to see if the temp would exceed 250; well it did and made it to over 600 degrees.[p]Before I attemp cooks longer than this, what do I need to do to keep the fuel adequate for really long cooking times yet reduce the amount I need to open the dome. I guess it is ok once or twice during cooking but I know opening the dome is a general "no no". Thanks.