ChlorForce M15 is a high quality liquid chlorine treatment or shock treatment for swimming pools. ChlorForce M15 is to be added at the required dosage level directly to the pool, ensuring that the product is distributed as evenly as possible. Circulate for as long as possible. ChlorForce M15 is used as shock treatment, as a guide 400ml of fresh ChlorForce M15 will increase the free chlorine level by 1ppm in a 45,000 litre pool. Free Chlorine levels must be maintained at between 1-3ppm.