Zodiac Spa Chlorine Sanitiser controls bacteria and viruses in spas. Keep microorganisms away with protective products. By adding purifiers to a well-balanced spa, effective protection against bacteria, algae, and other harmful micro-organisms can take place. Unfortunately, this also applies to nasty micro-organisms. Keep them away with an effective spa sanitiser adding purifiers to a well-balanced spa, effective protection against bacteria, algae, and other harmful micro-organisms can take place. Zodiac Spa Chlorine - Spa and Hot Tub Sanitiser details 504g/kg Available chlorine present as Sodium Dichloroisocyanurate. Also contains 100g/kg Sodium Tetraborate Pentahydrate. Killa blackspot algae Metal-free formulation Slow release Specially designed for heated water. Our Spa Chlorine is effective against any microorganism that may try to make itself home in your spa or hot tub. Dosage Rates: 5g daily dosage per 1000L Initial shock treatment 35g per 1000L