17x27x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Promote pack of 50

pack of 50

and brews a mean plant tea

it works on contact to smother Erysiphales spores - the order of fungi that cause powdery mildew

depending on the extent of infestation

whether grown in soilless mixes or soil

17x27x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Promote pack of 50Nordic Pure Custom MERV 13 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