Our premium, quick dissolving, unstabilized granular chlorine shock. Packaged in convenient 400 gram bottles. 1 bottle treats 40,000 litres. Add to bucket of water to mix prior to pouring around edges of pool. This product is best applied in the evening. Ideal for use when a strong chlorine shock is needed; algae treatments, chlorine demand issues, superchlorination treatments. Can be used as a regular preventative shock.