There is no definitive answer to this question as it will depend on a number of factors, including the size and breed of your chickens, the climate you live in, and how much water they are likely to consume. However, as a general rule of thumb, it is recommended that you place water nipples around 18 inches apart. This will ensure that each chicken has easy access to a water source, and that there is plenty of room for all of them to drink without overcrowding.