20x20x4 (3 5/8) Pleated MERV 7 Air Filters 2 Pack pest-and-disease-control Two separate set points can

Two separate set points can be adjusted from 4 to 7 pH and 900 to 1800 ppm (mg/L)

Golden (Globodera rostochiensis) nematodes

and other garden and hydroponic pests

(6) 6' Soil Probes

Size: 1 gal

20x20x4 (3 5/8) Pleated MERV 7 Air Filters 2 Pack pest-and-disease-control Two separate set points canImportant 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