For germs, your fresh water tank is like a big swimming pool - jump in and feel good. After just a few hours, bacteria & co. multiply many times over. You can usually recognize this by a slimy film on inside of your fresh water tank or in your pipes. This biofilm offers bacteria optimal living conditions to multiply and at the same time protects you from external influences. It is therefore advisable to prevent biofilm from forming in the first place, thus depriving bacteria & co. of any basis for life and effectively combating possible pathogens. BAUA No. N-65554. Attention: H410