It is essential that a toilet fluid should kill harmful bacteria and germs to prevent them from multiplying. Elsan Blue’s powerful anti-bacterial formula kills them on contact whilst eliminating unpleasant odours. Elsan Blue and Double Blue are the only fluids you can buy that exceed British Standards. That’s why Elsan toilet fluids are chosen by caravanners, and boating and camping enthusiasts alike. Dosage: 60ml of Elsan Blue to the waste holding tank for every 10 Ltrs of waste tank capacity, then add 2-3 Ltrs of water.