14_1/2x19x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack grow media Outside Diameter: 40

Outside Diameter: 40

Full Spectrum enhanced with Red

Keep your growing environment in balance by ensuring you have proper ventilation

Humic acid is a naturally occurring material found in soils

with full kill down to the root within 4–5 days for most weeds

14_1/2x19x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack grow media Outside Diameter: 40Nordic Pure Custom MERV 14 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