21x23_1/2x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack Pumps & Irrigation For the individual that wants

For the individual that wants a fully organic

Ferocious is a premium plant-optimizing additive that delivers concentrated forms of hydrogen and oxygen

while providing the best possible lighting for all Indoor Horticultural applications without fail or compromise

Not only is it easy

21x23_1/2x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack Pumps & Irrigation For the individual that wantsNordic 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