20x20x4 (3 5/8) Pleated MERV 10 Air Filters 1 Pack Meters & Solutions which can drastically impact nutrient

which can drastically impact nutrient uptake and yields

Classification Release Information:

Automatic 1 or 2 point pH calibration

5pcs per set*

20x20x4 (3 5/8) Pleated MERV 10 Air Filters 1 Pack Meters & Solutions which can drastically impact nutrientImportant 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