Lime water means lime water , but milk of lime is a kind of paste. Dilute solution of lime water Ca (OH) 2 , paste of milk of lime water and calcium hydroxide. Lime water is available by adding water to milk of lime , but to get milk of lime from lime water you have to give heat. Milk of lime is thicker than lime water. Lime water is used to wash the house , Milk of Lime is used to control insects