Calcium nitrate tetrahydrate is a colorless, hygroscopic crystalline salt widely valued as a highly soluble source of calcium and nitrate ions. It is commonly used in agriculture as a fast-acting, chloride-free fertilizer, particularly for crops sensitive to salinity and calcium deficiency.

Beyond agriculture, it is utilised in wastewater treatment, concrete admixtures, refrigeration salt solutions, and various chemical manufacturing applications. In construction, it acts as a set accelerator and corrosion inhibitor in certain cement systems.
Grade and impurity profile should be selected based on end-use, especially where chloride, magnesium, or heavy-metal limits are critical.