Use biocides safely. Always read the user manual and product data before use. Warning. Irritates the eyes. Highly toxic for waterbourne life forms, long-term injurious effects. Keep away from reach of children. Thanks to a combination of silver iones and chlorine these tablets work fast. After a 30 minute wait the tablets have gotten rid of bacteria and virus, and after two hours giardia as well. Keeps water safe for six months. 100 tablets (100 x 1 liter of treated water). Can be used when traveling and backpacking, and other situations where clean water is not to be taken for granted. And yes, admittedly the tablet will give water a noticable side taste. *Note!* A water filter or purifier tablets cannot remove the toxins created by algae bloom, and therefore do not make water containing said toxins safe to drink.