Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, or coconut husk
Made of galvanized steel, these dampers prevent air leakage into your fan setup. They are easy to install, fit directly onto the ducting, and prevent a back draft of air when the fans are switched off.