Boy, thought I would do my 8 1/2 lb bone-in turkey breast at some higher heat to get the crispy skin. 325-375º. To do this, I planned on using Playbox sand instead of water and around 3/4 of a pan of charcoal. Using the normal water in the pan, I can sometimes get around 300 to 325º but it does not stay there very long and usually will drop back to 275º or so. So, after 40 minutes, I had 300º, around 70 minutes I had this. Couldn't believe it. I had to askew the lid to relieve some of the heat. What are my options to control the heat better, using sand? The 'drill the holes in the dome' mod may help ?? Less Charcoal?? Gauge is new and was checked not long ago against an Accurite Oven temp gauge.