20x25x4 (3 5/8) Pleated Air Filters MERV 7 Plus Carbon 6 Pack hydro-systems Monitor EC regularly and adjust

Monitor EC regularly and adjust accordingly based on the crop and growth stage

Hps Equivalent - 2000W

Stronger corners and thicker all around than most other brands

Keep your productivity high and your risk level low when you wear our comfortable ValuGuard MP™ disposable coveralls

± 2% Full scale (for EC and TDS)

20x25x4 (3 5/8) Pleated Air Filters MERV 7 Plus Carbon 6 Pack hydro-systems Monitor EC regularly and adjustImportant 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