By John Brennan
Updated Mar 24, 2022
Calcium chloride (CaCl₂) is a highly hygroscopic, water‑soluble ionic compound. It is widely used as a de‑icing agent, drying agent, and in many industrial processes—including swimming pool maintenance, food preservation, and beer brewing. When CaCl₂ dissolves, it releases heat, so the solution will warm as the compound disperses.
Measure the amount of calcium chloride you wish to dissolve using a clean spoon or measuring device.
Pour cold water into a suitable container. The volume should match the amount of CaCl₂ you plan to use, whether you’re preparing a pool solution or an aquarium additive.
Slowly add the calcium chloride to the water. It should begin to dissolve rapidly.
Stir the mixture with a wooden spoon to accelerate dissolution. If the solution remains cloudy, add a little more water and stir again.
Because the dissolution of CaCl₂ is exothermic, always use cold water and a heat‑resistant container to avoid overheating. Never ingest solid CaCl₂—its heat release can cause burns inside the mouth. While CaCl₂ has low toxicity, consuming large amounts of the solution may irritate the stomach or gastrointestinal tract. The compound is a mild skin irritant, especially on moist skin, and can corrode certain metals over time.
