Surex 3000 is the trade name for Trichlor or other wise known as Chlorine Tablets.
Great as a slow dissolving sanitiser (to coincide with the use Surex OO2 if required).

Think of Surex 3000 as your secondary pool man slowly dispursing chlorine into the pool generally applied through floating dispsensers.

Applied in the pool & spa daily as a general rule - please follow your guidelines on label for application.