21x23_1/2x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack soil - Reduce the need for

- Reduce the need for fungicides

Its sleek design and IP66 connectivity makes it ideal for both single and multi-tier growing configurations

which contains carefully selected biological stimulants such as amino acids

DLC Certified: Download the certification here

21x23_1/2x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack soil - Reduce the need forNordic 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