Hello! I have been reading several Threads/ post in the forum about the use or lack of use of the water pan in the WSM, or any other smoker. I would like to first explain the main function of the water pan. The water pans main function is to help stabilize and hold the temp. for extended cooks between 180F to 270F. The steam from the water will in theory try to keep the temp. in the smoker around 212F, which is the boiling temp of water. This is in theory is the ideal temp. for the collagens to break down in the meats, and make it tender. (Meats such as brisket, pork shoulder(Boston Butt), rib's and whole turkey). It also serves as a heat deflector for indirect cooking, and is completely un necessary for shorter hotter cooks above 275F, such as chicken or Tri Tip. Also the steam from the water does nothing for the moister in the meat! However it can effect the flavor and tenderness of the meat! (this part is arguable!) Yes here is where we get into the science and theory part of everything. The steam( H2O) from the liquid in the water pan in theory mixes with or reacts with the smoke( nitrites and nitrates) from the charcoal/ wood causing nitric acid( HNO2) to form. This in turn reacts with the salts, fats, collagens, and proteins in the meat causing nitrites and nitrates to absorb in to the meat. Which also helps preserve, tenderize, and flavors the meat with that lovely smoke flavor!! The use of the water pan is completely optional (Your choice), but it can be useful!! I personally have had success with the water pan and with out the water pan!! Another thing I would like to add is please don't stress about the temperature on your smoker (WSM)!! ass long as it is with in 30 degrees (give or take) of your target temp. you are okay!! temperature fluctuations happen!! Because of climate, weather, quality of meat, or charcoal there are no constants in BBQ!! Just adjust your cooking times. Drink an adult beverage, and relax!