Aluminum Sulfate is a salt with the formula Al2(SO4)3. It is soluble in water and is used to reduce the pH of garden soil.
Ferrous Sulfate (Monohydrate, Heptahydrate)
Ferrous Sulfate denotes a range of salts with the formula FeSO4·xH2O. These compounds exist most commonly as monohydrate (x = 1) and heptahydrate (x = 7). Industrially, Ferrous Sulfate is mainly used as a precursor to Miscellaneous iron compounds. It is a reducing agent, and as is useful for the reduction of chromate in cement to less toxic chromium (III) compounds. It is also used to stain concrete and some limestones and sandstones a yellowish rust color.