20x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 1 Pack grow-light-ballasts 6 lbs Size 7" x

6 lbs Size 7" x 13" x 7"

and then add water to create the ideal environment for the bacteria

recycle timers

Direct replacement for Ona Carbon-Air (ON10052)

20x20x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 1 Pack grow-light-ballasts 6 lbs Size 7" xImportant 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 20x20x4 filter