16_1/2x21x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Grow Strong powdery mildew unless you deal

powdery mildew unless you deal with your root zone first

Elements Grow is a high nitrogen formula developed to encourage vigorous stem and leaf growth

with THE HOSE by AEROMIXER

Powder coated steel guards for increased durability and corrosion resistance

Heavy duty construction with galvanized steel

16_1/2x21x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Grow Strong powdery mildew unless you dealNordic 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