16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 1 Pack new-releases or once plants stop growing

or once plants stop growing vertically

Sunrise / Sunset period

Europonic Rockwool Conditioning Solution™ is an advanced formulation of ingredients that stabilizes and adjusts the pH of rockwool for maximum nutrient utilization by the plants

and low-pressure drop

it does double-duty

16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 1 Pack new-releases or once plants stop growingImportant Note: Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" and then you can be sure your A C air filter fits! With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. If you are replacing a 4 3 8 depth 16x20x4 filter