Remove the spilt calcium chloride crystals and moisture from the carpet by vacuuming the area thoroughly with a wet/dry vacuum.
Pour small amounts of hot water over the stain. This will dilute the calcium chloride. If you do not dilute the calcium chloride, the spill will get larger as it continues to absorb moisture in the air. The calcium chloride may also harm the carpet fibers. Vacuum the area again.
Continue to pour small amounts of water over the stain and vacuum the area with a wet/dry vacuum. Perform this process several times until all of the calcium chloride is removed.