Puriclean cleans and purifies all stored water systems in boats, caravans, motorhomes and coaches. It eradicates bacteria, viruses, biofilm, algae and fungi. This is an essential safeguard to health! It cleans up to 270L (60 Gal) tank and has a unique dual-purpose formula which both cleans and sterilizes in one easy action. For water carriers/containers: simply pour the powder in and leave to soak with water for 1-12 hours. For tanks and complete water systems: dissolve the powder in a plastic container then add to the system. Periodic use will ensure a clean healthy system for water storage. Puriclean can be used in all water systems including those with stainless steel boilers. The powerful action works without harming the components in the water system. Proven in use worldwide for 3 decades, Puriclean is easy to use. It is simply added to the water system and left to soak for 1 to 12 hours, then rinsed.