21x21x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack Air Filter up to 3-4x stronger than

up to 3-4x stronger than General Hydroponics

and they feature a highly precise microprocessor and four-way output control

Alg·A·Mic™contains a low level of NPK

Feeds up to 4 months

21x21x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack Air Filter up to 3-4x stronger thanNordic Pure pleated AC air filters are made of electrostatically charged synthetic materials that attract and capture most airborne particulates in your home or office. Each time air passes through a Nordic Pure pleated furnace filter, lint, household dust, pollen, dust mites, pet dander, baking flour, mold spores and other contaminants are removed. Our filter media prevents the growth of bacteria or mold, resulting in a much healthier living space.