The Applied Biochemists Algaetrine 2000 is a powerful algaecide that will efficiently prevent and remove all types of algae. It is a fast acting algae control product that will provide results fast, and will remove even the toughest algae, black algae which has a defensive coating that makes it harder to remove. Simply brushing and vacuuming in conjunction with this algaecide will make your pool surfaces return to a crystal clear state.