18x28x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Nutrients and Supplements an air stone that helps

an air stone that helps aerate the water

pH levels outside recommended ranges can lead to nutrient lockout and nutrient deficiencies resulting in stunted growth and poor appearance

Set your preferred voltage by clicking the power button three times

weeks before harvest of most fruiting and/or flowering crops

From hands-free monitoring to 2-way humidity-control technology that expertly adapts to the air around it without you lifting a finger

18x28x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Nutrients and Supplements an air stone that helpsNordic Pure Custom MERV 10 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