Many plants produce a strong pungent odor during flowering. The suction causes the hot air get away. Out of the grow room In order to avoid odor nuisance, it is necessary to use a filter. Generally one uses carbon filters. Carbon is a metal cylinder filled with activated carbon. Carbon has the ability to take. Fragrances per se The smell of the plant passes through the carbon layer and comes out from odorless. The extractor sucks the warm odorless air out. A good carbon filter is very important for indoor growing. Since the active carbon particles into force decreases as the time it is recommended to replace a filter after 3 times.