16x28x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack ventilation and ducting Single-junction electrode is well-suited for

Single-junction electrode is well-suited for general purpose applications

Activated by humidity (35%) and /or by lightly misting with water or you can add a moist sponge to a folded GRAND DADDY PAD

Hang the BlackBird at 20–24 inches above the canopy for flowering

This ballast's constant wattage output means no lamp flickering and with the flip of a switch it can be converted from MH to HPS ballasts

16x28x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack ventilation and ducting Single-junction electrode is well-suited forNordic Pure Custom MERV 7 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