20x25x4 (3 5/8) Pleated MERV 7 Air Filters 1 Pack spl_fluence Ionic PK Boost delivers the

Ionic PK Boost delivers the key mineral elements phosphorus (P) and potassium (K) in a pure form that is instantly accessible to the plant

Compatible with all growing mediums

electronic ballast

050 mg/hr and can cover up to 5

it helps the roots deal with abiotic stress (which includes drought

20x25x4 (3 5/8) Pleated MERV 7 Air Filters 1 Pack spl_fluence Ionic PK Boost delivers theImportant 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