HTH™ Chlorine Granules is calcium hypochlorite in granular form containing typically 68 – 70% available chlorine. Used for the treatment of water in swimming pools. Will destroy bacteria, viruses, fungi and algae. Dissolves quickly and will raise the chlorine level of water fast. Suitable for use with all kinds of water, including very hard water. Compatible with all types of filtering equipment. Available in 25kg drums.