11_1/2x21x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Environmental Controllers and vastly increases nutrient uptake

and vastly increases nutrient uptake for all plants

are both strong and durable

and it also features an internal clock with a back up battery to maintain accurate timing even in the event of a power outage

Verde Fire Grow is recommended for leafy plants and the vegetative stage of flowering and fruiting plants

Charcoal-based carbon filter loaded with 30 lbs bituminous charcoal

11_1/2x21x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Environmental Controllers and vastly increases nutrient uptakeNordic Pure Custom MERV 10 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