12_3/4x21x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack harvest-solutions Air stones will extend the

Air stones will extend the life of your nutrient solution

including Low Rise trays

Potassium and

16 oz Trinity

This results in long-lasting

12_3/4x21x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack harvest-solutions Air stones will extend theNordic Pure Custom MERV 8 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