I did my first cook yesterday with babby backs. I put in 1 1/2 gallons of water in the pan and full lump minon style, on new 2010 18.5. The temperature at guage went up to 300 and stayed there. Thirty minutes in I closed the two front vents by 1/3 and temp stayed at 255 for 2.5 hrs. Checked ribs, done but dry in rib rack. What can I do to drop temp to 200 to 220? Or should I have not used the rib rack? Any suggestions on vent settings would be apreceiated.