21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack trays With lower operating temperature

With lower operating temperature

and enhancement of the microbial population in the growing medium

or boiling

providing nearly tenfold savings on infrastructure with superior diffusion rates for the price

ornamentals and landscape plants

21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack trays With lower operating temperatureNordic Pure Custom MERV 13 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition