@casingstuffer We add water pans to pretty much everything we do in our Pk 100 smoker, what @Boudreaux says is correct, the best time to add it would be after the drying cycle has run but if you were to add it right away that wouldn’t be the end of the world. While the water pan does add humidity it is not going to add much, especially around 120° which is where your first hour should be. Adding a water pan might only add 5% additional humidity to your smoker but it is still worth doing!