The white phase: Rapid disinfection with active oxygen. The blue phase: Strengthens and prolongs the disinfection and prevents impurities and deposits. The red phase: Prevents precipitation of lime and minerals in the water. Instruction: The tablet is placed in a liquid chemical dispenser for pools. Important, do not put the tablet directly into the pool as it can damage the bottom of the pool. Dosage: A01 2 tablets every 4 days A02 3 tablets every 4 days