In softening plants, what type of acid is used to clean filters if they are troubled due to calcium carbonate?

In softening plants, hydrochloric acid is commonly used to clean filters that are experiencing issues due to calcium carbonate buildup. This is due to its effectiveness at dissolving the insoluble deposits formed by calcium carbonate. Hydrochloric acid, being a strong mineral acid, reacts with calcium carbonate in a manner that produces soluble calcium chloride, water, and carbon dioxide, allowing for the efficient removal of scale and restoring filter functionality.

Cleaning with hydrochloric acid is preferred in this context primarily because it is a powerful acid that can quickly address heavy scaling problems. In contrast, other acids such as sulfuric and acetic acid are either less effective for this specific type of deposit or are used in different scenarios within water treatment processes. Citric acid, while it can be used as a cleaner, may not provide the rapid and thorough descaling that hydrochloric acid achieves, making it less suitable for heavy calcium carbonate deposits typically found in softening plant filters.