This biological product removes all traces of atmospheric origin due to enzyme activity. Viano Biomix ATM Blackstain remover is to mix with water in a 1/5 concentration before application. Biomix ATM Blackstain remover is to apply with spreader or watering can an needs no scrubbing. After applying let the product do the work itself for a cupple of hours, than rinse well afterwords. Safe to human, animal and surfaces. It is used in the cleaning of tiles, terraces, wood, teak, glass, metal, roofs, gardenfurniture. When surface is heavy contaminated, repeat application.