What happens when you add ammonia to a salt solution that is growing crystals? Salt crystals form when water evaporates from a salty mixture. Adding certain chemicals can change how large those crystals get. You prepare four bowls. The first holds salt and water. The second adds bluing liquid (a laundry product). The third adds bluing and three tablespoons of ammonia. The fourth adds bluing and six tablespoons of ammonia. You place a sponge in each bowl and let the crystals grow for ten days. The bowls without ammonia grow small crystals about 2.5 mm tall. The bowl with the most ammonia grows crystals over 8 mm tall that overflow the bowl.