16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 1 Pack trays High-volume 400 CFM fan operation

High-volume 400 CFM fan operation performs complete air change within 2-10 minutes in a typical room size of 10′ x 10′ x 8′ (800 cubic feet)

Red Sodiums are recommended for situations where high output supplemental light is preferred

Other single part nutrients are clear with no fallout but in order for this to happen it has to be made a lot weaker so that the elements don't react

Sluggo is the proven

transporting the sun’s energy by delivering carbon to plants at robust rates

16x20x4 (3 5/8) Furnace Air Filters MERV 12 Pleated Plus Carbon 1 Pack trays High-volume 400 CFM fan operationImportant 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