Overview
After using the greenhouse film for more than a year or over, it is probably that the film may be covered with some microorganism that reduce the effectiveness of the film by limit the light transmission to the crop inside. Greenhouse film with anti-microbial additive works by inhibiting the growth of microorganism (yeast, algae, fungi, bacteria) on the film so the film stays clear and clean. This additive is working by staying in the layer of the plastic and work as long as the lifetime of the plastic.

algae on the greenhouse film which significantly decrease light transmission