In general, crockpots are sealed cooking appliances that are used for between four and ten hours at a time. During this cooking process it is usually not at a temperature high enough to boil the water. u003cbr/u003eu003cbr/u003eIn addition to that there is not a lot of steam when cooking with a crockpot which means that there is not a lot of water lost during the cooking process. So, in light of these facts you will not really need to put extra water in your crock pot.