Phresh Intake FiltersPhresh Intake Filters Phresh Intake Filters are designed with science in mind. They are proven to remove 98. 7% of all airborne contaminants. This filter provides exceptional air quality control in your grow room for up to 12 months. This filter has a galvanised wire mesh exterior which is not only sturdy, but also helps to evenly disperse air through the filter and the rest of the ventilation system. It also works well under pressure the Phresh