20x25x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 6 Pack post harvest Works best in warm weather

Works best in warm weather (60°F+)

splash resistant and have an easy-to-read display

the plant can best be fed with Root·Juice™during the first week(s)

This is especially useful to contain the spread of disease in your growing area

and aged forest products

20x25x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 6 Pack post harvest Works best in warm weatherImportant 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 20x25x4 filter