15_1/4x15_1/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack spl_dlw As the Bluelab Combo Meter

As the Bluelab Combo Meter is portable and does not require a power supply to operate

Increases resin production by weight during late flowering

They are more efficient

or medium to large scale gardeners with agricultural tents or limited plant counts

This exclusive formula is a universal supplement for both growth and bloom

15_1/4x15_1/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack spl_dlw As the Bluelab Combo MeterNordic Pure Custom MERV 14 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition