21_1/2x23_3/8x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack discounted Contact mode of action makes

Contact mode of action makes this a great choice as a resistance management tool

• Avoid prolonged exposure of the inoculum to direct sunlight

5" dome gives extra height for your taller cuttings

Note beginning reading and then test pH

Our onsite Carbon Analysis Laboratory allows us batch test

21_1/2x23_3/8x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack discounted Contact mode of action makesNordic Pure Custom MERV 12 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