20x25x4 (3 5/8) Pleated MERV 15 Air Filters 6 Pack pumps-&-irrigation A 4 stage filter array

A 4 stage filter array with UV Kit

Hanna Instruments Direct Soil HALO pH Electrode gives you the ability to measure

Each Nordic Pure 4” MERV 15 air filter will capture more than 90% of 1

and works with both MH and HPS lamps

so you can rest assured you're growing safely

20x25x4 (3 5/8) Pleated MERV 15 Air Filters 6 Pack pumps-&-irrigation A 4 stage filter arrayImportant 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