Some substances have the function of complexing inorganic salts, and precipitate salt-forming complexes in water to soften hard water. A substance having such a function is called a water softener. Such as: soda ash, some phosphate, NTA nitrilotriacetate, EDTA (disodium edetate). Softener is a highly effective chelating dispersant. It has excellent complexing power for metal ions such as calcium and magnesium. It is essential for textile printing and dyeing processes.