21x23_1/4x1 Exact MERV 14 AC Furnace Filters 6 Pack Environmental Controllers The all natural ingredients in

The all natural ingredients in our formula increase soil fertility and feed soil microorganisms while suppressing soilborne plant pathogens

hydroponic and ornamental crops

and armed with overheat protection

The non-refillable Bluelab Soil pH Probe is used to measure the pH levels of soil or media of cropping

Optional Upgrade to hardshell

21x23_1/4x1 Exact MERV 14 AC Furnace Filters 6 Pack Environmental Controllers The all natural ingredients inNordic Pure MERV 14 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. Each time air passes through a Nordic Pure pleated furnace air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores, smoke particles, virus carriers, coughs and sneezes, smog, allergens and other contaminants are removed. MERV 14 furnace filters are comparable to HVAC filters with the rating of MPR 2800.