Duo Tank Cleaner Concentrated is one of the newest members of Thetford’s well known Concentrated family! Powerful, concentrated, periodical cleaner for the waste-holding tank and grey water tank. For a long, clean and fresh life of both tanks! Removes limescale, encrusting and grease deposits Technical parts inside the tanks are cleaned as well Prolongs the lifespan of the tanks No scrubbing required! Cleaning without damaging the technical parts inside the tanks 0.8L = 4 cleanings of the waste-holding tank (4x200ml) 0.8L = 1 cleaning of the waste-holding tank (200ml) + 1 cleaning of the grey water tank (600ml) For best results use 2-3 times a year