New smoker here. I have a Napoleon Apollo vertical water smoker (very similar set up to the WSM). I have done a couple dry runs just to learn the nuances of my smoker. Today I smoked a small 6-ish pound pork butt using hickory. My problem was in controlling the heat. It seemed no matter what I did, the temp was always around 300. I had all three bottom vents barely open. I did not use a water pan. It was a very warm sunny day today. The butt turned out fine but because of the higher smoking temperature, it didn't take as long as I was expecting (about 5 hours). What can I do to get the temperature down further? Is it as simple as using the water lab?