Active ingredient: isocyanuric acid. pre-condition your pool water make chlorine last longer save your money 1)pre-condition your pool water to make chlorine last longer2)protects chlorine from the sun's damaging effects3)increase chlorine effectiveness4)powder, granular or tablet form5)packed in 1kg, 5kg, 10kg,25kg,50kg, 1000kg. Chlorine Stabilizer