First time with my new smoker.. lets hope they turn out. I have a propane 30" calebs, using mesquite chips.Cooking up two racks of spare ribs. I did have to cut them in half to fit, hope that doesnt hurt. How often am I gonna need to add more chips, and how long will a small bag last? I noticed I didnt put enough chips in just to get the smoker to 225*, and the temp dropped down quick when I added more.. is that normal and ok throughout the cooktime?