Humco SaltPetre Powder is a natural mineral with many uses in commerce and in magic. Magically speaking, Saltpetre has a long, long, long history in hoodoo as an agent of magical protection in spritual baths.Nearly unlimited shelf life; lasts virtually forever in storage.It has extremely high water solubility. Nearly all the formula dissolves easily in water, allowing the minerals and nutrients to be easily transported to plant roots.