Phresh® Carbon Filters The world's lightest carbon filters, at less than half the weight of competitors, Phresh® Filters are easier to handle, install, transport and remove. Phresh® Filters are used by labs, plant breeding, germplasms, tissue culture and commercial greenhouses for their total airstream filtration requirements. This professional-grade equipment is now available to hobbyists world-wide. Control your growing environment with the best filters available on the market.