There is no substantial difference between citric acid monohydrate and anhydrous citric acid, except that the former contains a crystal water, which is dissolved and the crystal water is not different from ordinary water. See your use as additives. Generally, the added materials contain a lot of water, and the addition ratio is usually very small. Therefore, the addition of these two kinds of citric acid hardly affects the moisture content, so it can be used. .
However, in food, no matter which one is used, it must be food grade. The words on the packaging are clearly marked with food additives, and the industrial grade is never available.
Make conditioners and scale inhibitors. Industrial grades can be used depending on the situation. Scale inhibitors, such as those involving drinking water, must also be food grade.