Can I mix with Pure-Castile Soap with Epsom salt?Updated a year ago

Epsom salt, also known as magnesium sulfate, is considered an acidic salt because when it dissolves in water, it creates a slightly acidic solution with a pH around 6. Since soap is alkaline, the two create a small acid/base reaction. Magnesium is highly reactive with soap, bumping the sodium or potassium ion off the head of a soap molecule and taking its place. This resulting magnesium soap is called lime soap, or more commonly "soap scum." You don't want this on your bathroom fixtures, and you definitely don't want this coating your pipes. Both are great ingredients separately--not together.