Water is an important but often overlooked nutrient. Most people concentrate on making sure they have adequalte supplies of water for bird consumption and evaporative cooling systems. However, there are many instances where water quality may be impacting performance whether it is a mineral or other contaminants in the water. Substances such as iron oxide can contribute to leaky drinkers or even reduce water availability. In many cases, bacteria can flourish in water systems and produce a slimy film known as biofilm that can obstruct water lines and filters, restrict water flow and impact bird performance.