AquaSPArkle Pure Spa Salt is graded to be suitable for use with spa salt water sanitising systems. Adding AquaSPArkle Pure Spa Salt to your hot tub enables the sanistising system to generate free chlorine which disinfects your hot tub water, keeping it safe and bacteria free. AquaSPArkle Pure Spa Salt contains no anti-caking agents that could otherwise affect the sanitising cell.