13x21_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Meters & Solutions Dimensions: equivalent openings to 22”

Dimensions: equivalent openings to 22” round on the inlet and outlet

The Magnum 18's inverter technology ensures lower operation costs

• Apply as a standalone with water or tank mix with other nutrients

It measures EC

accelerate growth and increase yield

13x21_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Meters & Solutions Dimensions: equivalent openings to 22”Nordic Pure Custom MERV 7 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