21_1/4x21_1/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack aaron Automatic 1 or 2 point

Automatic 1 or 2 point pH calibration

Move your lights back and forth across your growing area with a light mover

Saturate them with water

and your final yield

These tall (8 1/2" high)

21_1/4x21_1/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack aaron Automatic 1 or 2 pointNordic 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