16_1/4x21_1/4x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack complete-systems Electrical Conductivity (EC)

Electrical Conductivity (EC)

Also The Grow1 Digital Microscope uses 'Plug & Play' technology (included Mini CD ROM not required) and takes still photos

This is for a 3/4 in system

Pumping raw air into the nutrient solution

The black plastic helps prevent the growth and spread of algae

16_1/4x21_1/4x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack complete-systems Electrical Conductivity (EC)Nordic Pure Custom MERV 8 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